Thunder City begins with a problem Philip Reeve created for himself. He already finished Mortal Engines.

A Darkling Plain did not leave the original quartet begging for another lap around the scrapyard. It gave Tom, Hester, Wren, Anna Fang, Shrike and the whole broken Traction Era a brutal, beautiful ending. So when Reeve returns to this world with Thunder City, set just over a century before the original book and built around an entirely new cast, the question is not “is it nice to be back?”

Of course it is nice to be back. There are moving cities, undead war machines, civic stupidity and terrible people making terrible decisions in hats.

The real question is whether Thunder City earns the return.

Mostly, it does.

This is not Reeve trying to revive Tom and Hester. It is not a sequel trying to unpick A Darkling Plain. It is a new adventure from an earlier phase of the Traction Era, when Municipal Darwinism is already mad, but has not yet become the fully ravenous system we meet in the original books. The cities are still hungry. The people are still pretending the hunger has rules. That is where Reeve has found his way back in.

What is Thunder City about?

Thunder City introduces Tamzin Pook, a fighter in the Amusement Arcade. Her job is simple enough, if your idea of simple involves stepping into an arena and killing Revenants, dead brains housed in armoured engine bodies.

So that is a cheery way to grow up.

Tamzin knows survival. That is her world. Not family. Not safety. Not long-term emotional planning. Just the next fight, the next threat, the next mechanical corpse trying to end her day. Then Miss Torpenhow arrives and drags her into a larger problem involving the wheeled city of Motoropolis, which has been taken over by rebels after its leaders were killed.

Motoropolis needs saving. Unfortunately, the person who may have a claim to saving it is Max Angmering, a mayor-to-be who is not exactly screaming heroic destiny from the rooftops. Add in Hilly Torpenhow, washed-up mercenary Oddington Doom, assassins, city politics and Reeve’s usual appetite for putting strange people under terrible pressure, and Thunder City becomes a rescue mission, a road story, a found-family caper and a political restoration job with undead murder machines attached.

Which is to say, it is very much a Mortal Engines adventure.

Tamzin Pook, arena fighter and reluctant hero

Tamzin is the test of the whole thing.

A new Mortal Engines book cannot survive on machinery alone. The cities are wonderful, yes. The names are funny. The old-tech weirdness is delicious. But the original quartet did not last because London had tracks. It lasted because Tom was naive, Hester was terrifying, Shrike was heartbreaking and Anna Fang had the sort of mythic cool that made every page around her feel more charged.

Tamzin is not instantly iconic in that way, but that is not the brief. She works because Reeve builds her out of survival first and heroism second. She is not a wide-eyed museum boy like Tom. She is not the scarred blade of Hester Shaw. She is not Wren, carrying the resentments and curiosity of the next generation. Tamzin begins as someone shaped by spectacle and violence. Her body is useful. Her courage is practical. Her trust is limited for good reason.

That makes her a strong lead for this earlier Traction Era. She belongs to a world that turns suffering into entertainment and danger into a business model. The Amusement Arcade is a nasty little idea because it feels both absurd and completely believable. Of course people in this world would watch a child fight undead machines. Of course somebody would sell tickets.

Reeve does not overplay Tamzin’s damage. That helps. She is not written as a walking wound. She is capable, guarded and often funny by accident. Her growth comes from being forced into a crew, then slowly discovering that survival by itself is not much of a life.

Miss Torpenhow and the new crew

Thunder City has to do something that Bridge of Storms later benefits from: it has to build the crew.

That takes time. Not too much time, but enough that the early chapters carry the slight weight of setup. Reeve has to introduce Tamzin, explain the Arcade, establish the political mess around Motoropolis, bring Miss Torpenhow into the story, locate Max Angmering, and make Oddington Doom feel like more than a name found at the bottom of a drawer marked “Philip Reeve characters, very good ones.”

The good news is that the crew comes together well. Miss Torpenhow is not simply the respectable adult dragging the wild child into a mission. She has purpose, will and just enough exasperation to make her fit the world. Hilly gives the story another emotional angle. Max is useful because he is not the obvious hero the plot appears to need. Oddington Doom brings the battered mercenary flavour, the sort of man who sounds as though he has already survived three better adventures and two worse marriages.

Together, they give Thunder City its shape. It is not just Tamzin versus the world. It is Tamzin learning that a group can be a burden, a risk, a nuisance and, inconveniently, the thing that saves you.

Revenants, Stalkers and Reeve’s undead machinery

The Revenants are one of Thunder City’s best hooks because they give the book a clear connection to one of the great Mortal Engines obsessions: what happens when a person becomes a weapon and the machinery refuses to let them rest?

The original books gave us Stalkers, and with Shrike, Reeve found one of the strangest emotional centres in the whole saga. Shrike was frightening because he was a killer. He was unforgettable because he was not only a killer. He carried grief, memory, loyalty and a broken echo of love inside the metal.

Thunder City does not simply remake Shrike. Smart move. You do not improve on that character by photocopying him and adding more rivets. The Revenants begin as spectacle and threat, which fits Tamzin’s arena life perfectly. They are bodies turned into entertainment. Dead brains in armoured engines. The old horror of the Traction Era, repackaged for applause.

That is grim, and it should be. Reeve has always understood that the nastiest ideas in this universe are not hidden in secret labs. They are often public, civic, ticketed and well-lit.

The return of civic lunacy

Reeve’s cities are never just machines. That is why the setting still works.

A lesser version of Mortal Engines would be satisfied with “big city has wheels.” Reeve knows the wheels are only the start. What matters is the society built on top of them: the slogans, the markets, the cowardice, the vanity, the politics, the absurd civic pride and the terrible belief that if a system has been running for long enough, it must be sensible.

Thunder City has that flavour. The Amusement Arcade is not just a colourful location. It tells you what this era finds entertaining. Motoropolis is not just a threatened city. It is a political problem with engines attached. The whole book works best when it shows this earlier world pretending it still has order, while the logic of traction cities keeps dragging everyone toward appetite and collapse.

That is the sly thing about setting this book before Mortal Engines. The world is not as far gone as it will be later, but it is already sick. The manners are better. The disease is the same.

The pace: slower to ignite, strong once moving

Thunder City is not as immediately streamlined as Bridge of Storms, and that is understandable. This is the setup book. It has to build the engine while driving.

The opening has plenty going for it. Tamzin in the Arcade is a strong image. The Revenants give the book teeth. Miss Torpenhow’s mission gives the story a destination. Still, the book takes a little while to click into its best rhythm because it is doing a lot of foundation work.

Once the crew has formed and the larger political problem sharpens, Thunder City becomes more confident. Reeve is very good at movement once his pieces are on the board. He writes action cleanly. He does not stop every three pages to explain the bolts. He gives just enough detail to make a place feel strange, then gets on with the trouble.

That directness matters. Reeve’s prose is one reason these books remain so readable. He can make a strange world feel full without making the reader carry a sack of lore up a hill.

What Thunder City is really about

Under the adventure, Thunder City is about survival as performance.

Tamzin has learned to live by turning danger into a show. The Arcade has learned to profit from that show. The crowd gets excitement. The system gets money. The fighter gets another day alive, if she is lucky. That is not just backstory. It is a nasty little model of the whole Traction Era.

Cities eat cities and call it economics. Arenas feed children to Revenants and call it entertainment. Rebels seize a city and call it justice, or necessity, or whatever word makes the violence sound cleaner. Reeve’s world is full of people renaming appetite until it sounds respectable.

That is where Thunder City has more bite than its adventure shape first suggests. It asks whether a city can be saved without preserving the systems that made it corrupt in the first place. It asks whether survival is enough. It asks whether a person built for fighting can become something other than a weapon.

Those are good questions. Reeve does not always dig into them as deeply as he might, but they give the book weight beneath the chase, jokes and machinery.

Should new readers start with Thunder City?

You can start here, and Reeve has clearly designed Thunder City to be accessible. None of the original quartet’s main characters are required reading for the plot. The book takes place long before their time, and Tamzin’s story stands on its own.

Still, the best entry point remains Mortal Engines. That is where the world hits hardest. That is where London first comes roaring over the horizon. That is where Hester Shaw cuts through the usual shape of adventure fiction like a knife through polite society.

But if a younger reader finds Thunder City first, or if an old fan wants a cleaner route into Reeve’s newer work, it is a perfectly reasonable place to begin. For anyone trying to map the wider saga, the site’s guide to the best order to read the Mortal Engines books remains the safer route.

What works best

Thunder City works because Reeve finds a new angle instead of picking through the old wreckage.

Tamzin is a solid lead. The Amusement Arcade is a strong opening concept. The Revenants give the book a sharp link to the saga’s post-human horror without simply copying Shrike. Miss Torpenhow and the rest of the crew bring warmth, irritation and momentum. Motoropolis gives the adventure political stakes rather than just a destination.

Most importantly, the book feels like Reeve is expanding sideways. He is not undoing anything. He is not asking us to pretend the old ending did not matter. He is simply moving to another part of the map and asking what the Traction Era looked like before it became the full nightmare we already know.

That is the right instinct.

What does not hit quite as hard

Thunder City’s main weakness is that it sometimes reminds you how hard Mortal Engines is to equal.

That may be unfair, but it is unavoidable. Anyone returning to this world brings baggage. Hester. Shrike. Anna Fang. The first sight of London. The terrible beauty of A Darkling Plain. That is a lot for a new adventure to stand beside.

Thunder City does not always have that level of emotional force. Its funny parts are good, but not always as sharp as Reeve at his nastiest. Its dark parts are effective, but not always as haunting as the older books. Its themes are strong, but sometimes the adventure moves on before they can fully bruise.

That does not make the book weak. It makes it a return, not a culmination. It is a lively, clever, slightly lighter adventure in a world that once broke our hearts. Those are different jobs.

The verdict

Thunder City is a successful return to the Traction Era because it understands the one thing it must not do: disturb the grave.

It leaves Tom and Hester’s story alone. It does not try to make the original quartet smaller by turning its ending into another stepping stone. Instead, it moves backward, sideways and into a younger, slightly less savage version of the world, where the machinery of hunger is already turning but has not yet chewed everything to pieces.

As a novel, it is fast, inventive and easy to like. It has Tamzin Pook, Revenants, a strong crew, a city in need of saving and enough civic madness to make the return worthwhile. It is not the peak of the Mortal Engines saga, but it is a very good way back in.

If Thunder City has a flaw, it is that it carries the setup burden. It has to restart the engine. It has to introduce the crew. It has to prove this earlier era is worth visiting. That makes it a little less sleek than Bridge of Storms, but no less important to this new sequence.

By the end, Reeve has done what he needed to do. He has opened a new door into the Mortal Engines world without vandalising the old one.

How Thunder City leads into Bridge of Storms

Thunder City’s biggest success may be that it makes sequel Bridge of Storms possible.

That sounds like faint praise, but it is not. Starting a new Mortal Engines sequence is hard. Reeve has to convince readers to care about a different cast in a different period of the same world, without leaning too heavily on the old names. Thunder City does that work.

Bridge of Storms gets to arrive with the crew already formed, the tone already set and Tamzin already established as someone worth following. Thunder City has the harder job. It has to persuade us that this new corner of the Traction Era is not just a side quest. By the end, it has done enough.

If Bridge of Storms is the chase book, Thunder City is the ignition book. It gets the machine running.

Related Mortal Engines reading

• Mortal Engines, a second time around review
• Infernal Devices by Philip Reeve book review
• Our A Darkling Plain book review
• Review of Night Flights by Philip Reeve
• Bridge of Storms, the sequel to Thunder City
• What is the best order to read the Mortal Engines series?

Bridge of Storms is the sequel to Thunder City and takes place long before Tom Natsworthy meets Hester Shaw, before London becomes the full metal monster we know from Mortal Engines, and before Municipal Darwinism has completely eaten whatever manners the world still had left.

That is the key to the book. Philip Reeve is not trying to reopen the ending of A Darkling Plain. He is not dragging Tom, Hester, Wren, Shrike or Anna Fang back on stage for one more bow. Thank goodness. Their story had an ending, and a pretty damn good one.

Instead, Bridge of Storms returns to an earlier Traction Era, when cities still eat other cities, but the system has not yet reached the full brutality of the original quartet. There are still rules, deals, civic rituals, old institutions and a thin layer of respectability spread over the hunger. It is civilization on wheels, pretending it is not also a food chain.

The story follows Tamzin Pook and the crew of the Fire’s Astonishment as they become tangled in the fate of Museion, a university city trapped in a mountain valley known as the Frying Pan. Museion is one of those classic Reeve ideas that sounds ridiculous for three seconds, then begins to make horrible sense. It is a city built around knowledge, books, collections, records and precious things from the past. Its people want to reach London because being absorbed by London may preserve their learning better than being eaten by something worse.

That is pure Mortal Engines logic: grim, comic, practical and completely mad. A city wants to be eaten so its books might survive.

Naturally, the plan goes wrong. Predator suburbs are circling. Internal politics are not helping. Tamzin’s crew is pulled into danger. The chase begins, and Bridge of Storms quickly becomes what Reeve clearly wanted it to be: a proper city-chase story in the Mortal Engines world.

That is why the book works. It has a clear engine. It knows where it sits in the wider saga. It does not try to out-tragedy A Darkling Plain or recreate the shock of meeting Hester Shaw for the first time. It simply climbs back into the old machine, gives it fuel, and lets the thing roar.

The old Mortal Engines feeling is still there

The best thing about Bridge of Storms is that it feels like it belongs. That sounds easy. It is not.

Returning to a beloved fictional world is dangerous. Do too little and the book feels unnecessary. Do too much and it becomes a guided tour through old references. Mention every familiar piece of lore and the story turns into homework. Avoid the old lore completely and the book feels as if it is wearing someone else’s coat.

Reeve mostly avoids those traps. Bridge of Storms has the right smell of rust, oil, wet wool, old tech, bad politics and poor civic planning. The names feel right. The cities feel ridiculous in the correct way. The danger has that familiar Reeve quality where the absurd surface idea is carrying something sharper underneath.

The book is not simply saying, “Remember Mortal Engines?” It is saying, “Here is another angle on why this world is doomed.” That is better.

Tamzin Pook and the crew

Tamzin Pook is not Hester Shaw. That is not a criticism. No one is Hester Shaw.

Hester remains one of Reeve’s great creations because she was never softened into the usual shape of a young adult heroine. She was damaged, angry, frightening, loyal, selfish, brave and dangerous. She did not become more acceptable as the story went on. In some ways, she became worse. That is what made her so compelling.

So any new lead in this universe has a problem. The reader keeps looking for the scarred girl with the knife. Bridge of Storms is wise enough not to replace her.

Tamzin is a different kind of character. She is tough, capable and still forming herself under pressure. She gives the book a human centre, but the emotional force of Bridge of Storms is not hers alone. This is an ensemble adventure, and the crew around her does much of the lifting.

That is where the book finds its warmth. Oddington Doom, Max Angmering, Hilly Torpenhow and Vespertine all bring different kinds of energy to the story. Some are comic. Some are useful. Some are damaged in ways that are not played too loudly. Reeve has always been good at making side characters feel as if they had a life before the reader met them, and that skill is still here.

Vespertine is the standout. She is a Revenant, armoured, undead, terrifying and built for violence. In a lesser book, that would be the whole joke. Big scary dead thing does big scary dead thing work. Reeve gives her something more useful: tenderness. Her concern for Small Cat gives the book one of its best emotional threads.

That may sound minor, but it gets close to one of Reeve’s oldest tricks. He understands that the supposedly monstrous character can reveal more humanity than the polished citizens around them. Shrike did that. Anna Fang did it in a colder, sadder way after her transformation, a point that made Night Flights such a welcome late addition to the Mortal Engines shelf. Vespertine belongs to that tradition without feeling like a copy.

Also, Small Cat is a good literary decision. No further argument needed.

The chase gives the book its engine

Bridge of Storms is built around pursuit, and the structure suits Reeve.

Some adventure books mistake speed for drama. They throw the reader into noise and hope nobody notices that nothing meaningful is happening. Reeve is better than that. The movement in Bridge of Storms keeps forcing decisions. Characters are separated. Loyalties are tested. Museion’s strange plan becomes more complicated. The wider world presses in.

The chase works because it is not only about reaching a destination. It is about what people are willing to preserve, trade away or destroy along the route.

Museion is a strong idea because it turns the usual Mortal Engines predator-prey model sideways. In the original book, London was empire with engines. It was hunger dressed as civic destiny. Here, London is still dangerous, but Museion’s situation makes the question more uncomfortable. What if being eaten is not the worst outcome? What if survival means surrendering yourself to a larger system and hoping some part of you remains intact?

That is proper Mortal Engines material. A mad surface. A nasty little moral machine underneath.

The pace is both strength and weakness

The book moves quickly, and most of the time that is exactly what it should do.

Reeve’s prose remains clean and direct. He does not bury the reader under fake-steampunk decoration. He gives you the city, the threat, the joke, the bit of broken history and the next bad thing coming over the horizon. The pages turn because the writing is built for motion.

The trade-off is that some emotional beats could use more space. Bridge of Storms is not as devastating as A Darkling Plain. It does not have the first-book shock of Mortal Engines, where every new idea felt like Reeve had kicked open another door in the world. It does not have the bruised family tension of Infernal Devices, where Wren’s story cracked open the mess Tom and Hester had made of love, parenthood and survival.

This is a lighter book. Not thin. Not empty. Just lighter. For younger readers, that may be a virtue. For older readers who came to the series for the emotional damage as much as the city-eating, the book may feel a little brisk in places. A few moments could have landed harder if Reeve had let the silence hang longer.

Still, that is a measured complaint. Bridge of Storms is not trying to crush the reader. It is trying to run, and it runs very well.

The worldbuilding remains Reeve’s great weapon

The real star of Bridge of Storms is still the world itself.

Reeve’s great achievement with Mortal Engines was never simply “moving cities.” That was the hook. The deeper achievement was making those cities feel like the logical end point of bad history, bad politics and bad appetite.

Municipal Darwinism is stupid, but it is a believable kind of stupid. It is the sort of stupid idea people would defend if it made them rich, powerful or temporarily safe. That is why the setting still has bite. The traction cities are not just cool machines. They are class systems, empires, markets and museums on wheels. If you need the nuts and bolts of the idea, the site’s earlier guide to how traction cities work is still useful background before diving into this newer sequence.

Bridge of Storms understands that. Museion sharpens the theme beautifully. A city of knowledge trying to survive by being absorbed is funny, sad and grimly believable. It lets Reeve ask what civilization actually means when everything is moving, consuming and forgetting.

Is civilization the city? The books? The people? The system that protects them? Or just the story the powerful tell while deciding what gets saved and what gets fed into the jaws?

That is the sort of question Reeve can smuggle into a chase scene without making the book feel like a lecture.

How it compares with Thunder City

Bridge of Storms feels more confident than Thunder City.

That is not a knock on Thunder City. First books in a new sequence have to do heavier setup work. Thunder City had to introduce Tamzin, establish the earlier Traction Era, build a crew, and convince readers that Mortal Engines could continue without the emotional gravity of Tom, Hester, Anna Fang and Shrike.

Bridge of Storms gets to move faster because that work has already been done. The crew has shape. The world is running. The relationships carry some history. Reeve can throw the characters into danger without spending half the book handing out introductions.

That makes this sequel feel sharper and more purposeful. It is not just another visit to the universe. It has a clean central engine: get Museion moving, keep it alive, survive the chase, and deal with every awful thing that follows.

Is Bridge of Storms as good as the original quartet?

Not exactly, and that is probably the wrong test.

The original Mortal Engines Quartet became powerful because it kept widening and darkening. Mortal Engines introduced the world. Predator’s Gold expanded the map. Infernal Devices turned the story inward through Wren and the broken family Tom and Hester had built. A Darkling Plain brought the whole thing to a brutal, beautiful end, with MEDUSA, Stalker Fang, ODIN and all the old sins finally coming due.

Bridge of Storms is not playing that game. It is not the grand finale. It is not the origin of Tom and Hester. It is not trying to carry the emotional burden of the whole saga.

It is a chase story set in an earlier, slightly less ruined version of the world. Judged that way, it succeeds.

The better question is not whether it equals A Darkling Plain. The better question is whether it still feels like Philip Reeve’s world. The answer is yes. The engines sound right. The jokes are sharp. The danger has teeth. The machinery of civilization still looks one bad decision away from eating itself.

Should new readers start here?

You could read Bridge of Storms without reading the original quartet, but I would not recommend making it your first stop in the wider Mortal Engines universe.

Start with Mortal Engines if you want the real ignition point. Start with Thunder City if you want this newer sequence in order. Start with Bridge of Storms only if you have found it by accident, liked the cover, and enjoy entering fictional worlds through the side door while everyone else is already shouting about missing cats, undead soldiers and moving cities.

That is not the worst way to live, but it is not the cleanest way to read this series. The site’s guide to the best order to read the Mortal Engines books remains the better route if you are still mapping the whole thing out.

What works best

Bridge of Storms has a strong central idea, and Reeve does not waste it.

Museion is memorable. The city chase gives the book focus. The crew dynamic is warm without becoming soft. Vespertine and Small Cat bring the kind of strange emotional texture this universe needs. The pace is strong. The humour is dry. The lore connections are present without turning the novel into a reference manual.

Most importantly, the book feels written rather than manufactured. That matters. A return to a beloved universe can easily become maintenance work. Polish the old machine, point at familiar parts, invite the fans to clap. Bridge of Storms does better than that. It climbs into the machine and drives it.

What does not hit quite as hard

The main weakness is emotional compression.

The book is so committed to movement that a few character turns and moments of consequence pass quickly. There is danger, but not always lingering dread. There is feeling, but not always the ache that made the best parts of the original quartet stay in the mind for years.

Older readers may notice that most. The novel reads a little younger than the bleakest parts of the earlier books, and that may be entirely deliberate. Bridge of Storms is not trying to be the darkest Mortal Engines book. It is trying to be a fast, strange, lively adventure in the same world.

On that level, the lighter touch is not a failure. It is a choice. Whether it is the choice every longtime fan wants is another matter.

The verdict

Bridge of Storms is a strong sequel to Thunder City and a welcome return to the Mortal Engines universe.

It does not replace the original quartet and does not try to. It lacks the tragic force of A Darkling Plain and the first-contact thrill of Mortal Engines, but it has its own clear purpose: a chase across an earlier Traction Era, built around knowledge, survival, loyalty, old systems and bad civic decisions with engines attached.

That is a very good Philip Reeve setup.

The book is fast, funny, inventive and confident. It gives us Tamzin Pook and her crew in better shape, a university city with a wonderfully grim survival plan, a memorable Revenant, Small Cat, and enough rusty madness to prove the world still has plenty of life in it.

If Thunder City was Reeve proving he could return to Mortal Engines without breaking the old spell, Bridge of Storms is him pushing the throttle forward.

Related Mortal Engines reading

• Mortal Engines, a second time around review
• Infernal Devices by Philip Reeve book review
• Our A Darkling Plain book review
• Review of Night Flights by Philip Reeve
• Thunder City, the new Mortal Engines novel
• What is the best order to read the Mortal Engines series?