Thunder City may be a prequel, but it roars from the garage like the lead engine of the whole Mortal Engines convoy. Philip Reeve drops us a century before Tom and Hester’s escapades into a moment when traction cities still clung to chivalry, hunting codes, and the polite lie that eating a neighbour is sport rather than a war crime. Over four hundred pages, he blows that veneer to scrap, showing how honour rusts into brute appetite.
The End of Chivalry
We open in Margate, a raft town rebranded as a bloody Amusement Arcade where orphan slave Tamzin Pook hacks apart clockwork Revenants for sport. Her world is one iron rule: swing first, breathe later. The story then cuts to Thorbury, nicknamed Thunder City, a predator that still believes in manners. This illusion shatters when the exiled planner Gabriel Strega hijacks it in a Trojan-suburb stunt. Citing the Scriven wars as proof that honor is obsolete, he declares that cities must grow or die. With a single gunshot, municipal manners are dead, and Strega begins transforming the city into a ruthless super-predator.
Strega’s villainy is compelling because it's ideological. He sees himself as a realist, tearing away a polite fiction that was doomed to fail. He argues that the old hunting codes were a weakness, and that to survive in the brutal logic of Municipal Darwinism, a city must embrace its true, rapacious nature. He doesn't want to break the rules; he wants to fulfill them.
An Unlikely Alliance
The resistance is born from an unlikely partnership. Miss Lavinia Hilly Torpenhow—schoolteacher, historian, and unexpected freedom fighter—smuggles the mayor’s children out of the city and sets off to find a champion. Her quest leads her to Margate's deadliest gladiator, Tamzin. Their jailbreak is pure set-piece magic, and by the time the dust settles, the novel's core dynamic is forged: Hilly's tea-sipping, treaty-quoting morality fused with Tamzin's feral, traumatized survival instinct.
Tamzin’s arc is the novel’s spine. Freed from the arena, she is not instantly heroic; she is jumpy and convinced kindness is a con. Her gradual thawing is riveting as she learns to wield righteous fury instead of reflex violence. She is a clear precursor to Hester Shaw, another scarred girl forged in violence who must find a purpose beyond mere survival. Hilly, meanwhile, is the perfect foil, a woman of genteel upbringing forced into guerilla tactics, dragging everyone toward their better selves through sheer moral gravity.
The Cost of Progress
Thematically, Reeve explores the brutal cost of "progress." Strega tears through Thorbury’s green spaces to make room for new engines, echoing the urban sprawl William Blake railed against. Parks are paved, allotments uprooted, and the city’s lungs fill with soot. Reeve lingers on the toppled oaks and broken glasshouses, making the reader feel nature’s death rattle beneath the steel. This is the birth of the "Gut" on a smaller scale; the more efficient and powerful Thorbury becomes, the less human and humane it feels.
The villains embody this theme perfectly. The sadistic Dr. Mortmain represents pain as spectacle, a circus barker selling cruelty for profit. Strega, however, is ideology with teeth. He is the logical conclusion of an industrial society that has forgotten its soul. One character muses that perhaps the city was always hungry and Strega merely fed it, a dark idea that lands like prophecy: remove one tyrant, and another will rise unless the idea itself is starved.
The Paradox of Choice
Reeve threads a Blakean lament through the carnage, but also a philosophical paradox. The name of Strega’s mercenary crew, the "Boethius Brigade," nods to the sixth-century philosopher who wrestled with free will versus divine foreknowledge. Reeve turns this into narrative fuel. Do the choices of individuals matter if the gears of history are already grinding in one direction? Hilly fights for a gentler path, Tamzin claws for freedom, and Strega accelerates the march, yet the wheels of Municipal Darwinism keep rolling.
The novel’s final pages hammer this point home. Even after Strega falls, Thorbury continues its industrial upgrade, proof that a single victory cannot derail destiny. Free will chooses the speed; history has already laid the road. It’s a tragically powerful idea that resonates through the entire saga.
A World at the Crossroads
Lore collectors will swoon. We tour Paris on caterpillar tracks, glimpse Zagwa’s submarine empire, and meet outlaw engineers selling animal-brain cyborgs because human Stalkers are banned. The novel’s chronology is clever, slotting it into a time when the world was at an ethical crossroads. London’s MEDUSA nightmare is a known fable, but predators still believe bigger jaws equal safety. Strega bends that fable into a blueprint, and Thorbury follows.
Is Thunder City essential to the saga? Absolutely. It fills a historical gap and explains how traction civility eroded into engine-oil nihilism. More importantly, it is a crackling standalone adventure. It may not reach the operatic heights of A Darkling Plain, but it never tries. Reeve opts for a road-movie vibe: smaller stakes, sharper focus, and a punk-rock heart beating under the brass.
Most prequels feel like footnotes. Thunder City feels like main text—gritty, generous, and alive. By the time Tamzin, Hilly, and company sail off in a patched-up gunship, you are hungry for their next gig and freshly wistful for an age doomed to end in fire. The traction engines roll on. The ride is still wild. And with Thunder City, Philip Reeve proves he hasn’t run out of fuel; if anything, he just stoked the boilers for another lap around the Hunting Ground.
