The Mortal Engines Quartet (Hungry City Chronicles in the United States), also known as the Predator Cities Quartet, is a series of epic young adult science fiction novels by the English novelist and illustrator Philip Reeve. He began the first volume of the series, Mortal Engines, in the 1980s, and it was published in 2001. Reeve then published three further novels, Predator's Gold (2003), Infernal Devices (2005), and A Darkling Plain (2006).
The series is set thousands of years in the future, after the Sixty Minute War has devastated Earth. It tells the stories of young adventurers in the Traction Era, when moving cities roam the wasteland, attacking and devouring each other for resources. The novels have won a number of awards, including the Nestlé Smarties Book Prize in 2002 for Mortal Engines, the 2006 Guardian Children's Fiction Prize, and the 2007 Los Angeles Times Book Prize for Young Adult Fiction for A Darkling Plain.
A companion piece entitled The Traction Codex was released in 2011, and was expanded into The Illustrated World of Mortal Engines by Reeve and Jeremy Levett and published in 2018. Additionally, a collection of short stories set before the series called Night Flights was published the same year. A prequel series, Fever Crumb, set 600 years before the events of the Quartet, was published between 2009 and 2011. In March 2020, Reeve said, "too much time has passed since I wrote the other books, it's hard to go back to that world" and that he did not intend to publish further books related to the Mortal Engines universe. However in February 2024, Reeve announced the creation of a new Mortal Engines standalone prequel novel, entitled Thunder City, would be released later in the year. This was followed by a second book Bridge of Storms in 2026.
Title The title is a quotation from Act III, Scene III of William Shakespeare's play Othello ("Othello: And O you mortal engines whose rude throats/Th'immortal Jove's dread clamors counterfeit..." – Line 356/357).
Plot Mortal Engines
The book starts with the Traction City of London chasing and catching a small mining town called Salthook. In the "gut" of London, where towns are stripped for resources, Tom Natsworthy, a teenage Apprentice Historian, meets Thaddeus Valentine, the Head of the Guild of Historians, and his daughter Katherine. Hester Shaw, a teenage resident of Salthook, attempts to assassinate Valentine, and escapes through a chute. When Tom informs Valentine of Hester's name, Valentine pushes him into the chute. Tom and Hester recover outside London within the Hunting Ground and follow the city's tracks.
The pair board a small town called Speedwell, where they are drugged to be sold as slaves. Tom and Hester escape and fly with pilot Anna Fang aboard her airship Jenny Haniver to the neutral flying city of Airhaven, where they are attacked by Shrike, a cyborg "Stalker" sent by London Mayor Magnus Crome to kill and retrieve them. Tom and Hester escape in a hot air balloon. Hester reveals that when she was a child, Valentine injured her and killed her parents, after which Shrike took care of her. Desperate to avenge her parents, Hester traveled to London despite Shrike's pleas. Shrike followed but was captured by Crome and used to create more Stalkers for London.
The pair is then again confronted by Shrike, but before he can explain why he wants Hester to die, two chasing towns run him over. Tom and Hester manage to board the pirate town Tunbridge Wheels, which then wrecks on a coral reef and sinks. The surviving pirates mutiny and attempt to execute Tom and Hester, but Shrike intervenes and kills the pirates. He explains that Crome has agreed to resurrect Hester as a Stalker. She agrees to this, but Tom stabs Shrike, shutting him down and saving Hester.
In London, Crome sends Valentine on a "secret mission". Suspicious of her father, Katherine begins investigating events in London with the help of Bevis Pod, an Apprentice Engineer. They discover that Valentine salvaged an ancient weapon called MEDUSA, which the Guild of Engineers has reassembled inside St Paul's Cathedral. MEDUSA is then used to destroy a much larger city pursuing London.
Tom and Hester are rescued by Fang, who is revealed to be an Anti-Traction League agent. Together, they travel to the Shield Wall of Batmunkh Gompa, which protects the League. Fang suspects MEDUSA will be used by London to destroy the Shield Wall. She warns League Governor Khan, insisting that they should bomb London to destroy the weapon, to Tom's horror. Valentine infiltrates Batmunkh Gompa and cripples the League's airship fleet, then kills Fang in a duel and escapes in his airship. Tom and Hester fly back to London to stop Valentine and MEDUSA themselves.
Crome guides London toward the Shield Wall, intending to destroy it with MEDUSA and devour the League's settlements. Disillusioned and horrified by the weapon's destructive power, Katherine and Bevis conspire to destroy MEDUSA. They are caught and Bevis is shot by the Engineers, but they escape with aid from the Guild of Historians. Katherine travels up to St Paul's Cathedral, with Bevis disguised as her captor. Tom and Hester arrive, and Hester attempts to fight her way to Valentine and avenge her parents. Following an airship battle above London, Bevis is killed and Katherine reaches the cathedral. Inside, Valentine attempts to kill Hester, but Katherine jumps in the way and is fatally wounded. She falls onto a keyboard, causing MEDUSA to malfunction. Katherine dies before Valentine and Hester can get her to Tom for help.
Hester leaves with Tom in the airship while Valentine chooses to stay behind in London. MEDUSA misfires, obliterating most of the city and killing Valentine. Hester comforts a grief-stricken Tom as they fly away in the Jenny Haniver, apparently the only survivors.
Predator's Gold
Aboard Airhaven, Tom and Hester are joined by adventurer and author Nimrod Pennyroyal. They are soon pursued by the Green Storm, a fanatical splinter group of the Anti-Traction League, who seek the Jenny Haniver, which they believe was stolen from their deceased leader, Anna Fang. Despite evading the airships, Jenny Haniver is damaged above the Ice Wastes. They are rescued by Anchorage, a once-thriving Traction City ruled by Freya Rasmussen, who appoints Pennyroyal as chief navigator because of his purported experience traveling in North America, the city's destination. Hester becomes jealous of Tom's growing closeness to Freya, and is disturbed by sightings of "ghosts" in the city. Eventually she sees Tom kissing Freya, and leaves the city in the repaired Jenny Haniver. Hester sells Anchorage's course to Piotr Masgard, leader of the "Huntsmen" of the Traction City of Arkangel, who intends to capture the city through an airship invasion. As payment, she insists that Tom be returned to her after the capture.
Hester is then kidnapped by a Green Storm informant and taken to Rogue's Roost, where the Green Storm have converted Anna Fang's body into a Stalker. Sathya, the Green Storm commander, hopes Hester's presence will restore Fang's memories, but the resurrected Fang does not recognise herself or Hester. Sathya reveals that Hester's father was Thaddeus Valentine.
Tom realizes that Pennyroyal never went to America, but instead based his claims on an old map from the Reykjavík library. Tom also discovers that the "ghosts" are actually thieves operating out of a parasitic submarine-like limpet attached to the bottom of the city, who call themselves the Lost Boys. With their secret discovered, they kidnap Tom and leave for their base, the sunken city of Grimsby. Tom befriends Caul, a Lost Boy who tells him that Grimsby was founded by a man called "Uncle", who keeps the Lost Boys under constant surveillance.
In Grimsby, Uncle enlists Tom in a heist of Rogue's Roost. Tom infiltrates the base but is soon discovered and reunited with Hester in her jail cell. Realising that Uncle sent Tom to die as a diversion, Caul sabotages the operation, saving Tom and Hester. In the confusion, Stalker Fang kills all the remaining Lost Boys. She pursues Tom and Hester, but lets them escape aboard the Jenny Haniver when she seemingly recognises Tom; she then takes command of Green Storm from Sathya.
In Grimsby, Uncle severely beats Caul for his betrayal. He reveals that Fang was once a slave in Arkangel, but Uncle released her out of love. She betrayed him by building an airship and escaping from slavery. Uncle wanted to retrieve and reprogram Fang to become his slave. Caul is saved by a fellow Lost Boy, Gargle, who gives Caul the Reykjavík map.
Freya catches Pennyroyal secretly broadcasting a radio message requesting his rescue, and he admits he lied about traveling to America. Chased by Arkangel, Anchorage is captured by the Huntsmen, who leave it helpless on the ice. Tom and Hester return to the city; Hester liberates the inhabitants, killing Masgard and the Hunstmen in the process, whilst Tom confronts Pennyroyal, who accidentally shoots him in the chest. Pennyroyal then steals the Jenny Haniver and escapes. Arkangel still pursues Anchorage, but becomes trapped over thin ice, and Anchorage drifts out to sea on an ice floe.
Caul returns to Anchorage with the Reykjavík map and convinces the city to continue despite Pennyroyal's fraud. Meanwhile, Pennyroyal escapes to the Hunting Ground and publishes a book reimagining his time in Anchorage with himself as the hero, and Arkangel is evacuated and eventually sinks to the bottom of the ocean. In Asia, the Green Storm, under the leadership of the Stalker Fang, topples the old Anti-Traction League. Anchorage eventually arrives in North America to find it enough parts of it have greenery for them to settle. Hester takes comfort knowing the city is safe, and discovers that she is pregnant.
Infernal Devices
Sixteen years later, most inhabitants of the now-static city Anchorage-in-Vineland are happy with their new lives, except Wren Natsworthy, the teenage daughter of Tom and Hester. One night, she encounters three Lost Boys—Remora, Fishcake, and their older leader Gargle—who have come to Anchorage in search of the Tin Book, an artifact that contains the activation codes for orbital weapons left over from the Sixty Minute War. Gargle persuades Wren to join them.
Unaware that Gargle intends to sell the Book to the Stalker Fang, Wren steals it from the palace library. Meanwhile, Caul alerts Tom and Hester that Wren is missing. Believing that Wren is in danger, Hester shoots and kills Gargle and Remora. Devastated, Fishcake kidnaps Wren with the intention of taking her to Grimsby, but changes course after receiving an enticing communication from the raft resort of Brighton. Upon arrival at Brighton, the two are enslaved, the communication being a ruse. Nabisco Skhin, owner of the slave trade company, interrogates Fishcake, who reveals the location of Grimsby, prompting Brighton to destroy it with depth charges. Wren convinces Skhin to give them over to Nimrod Pennyroyal, now Mayor of Brighton, whom she can blackmail. When Skhin takes Wren to Cloud 9, Pennyroyal's floating palace above Brighton, she double-crosses Skhin and gives the Tin Book to Pennyroyal.
Tom, Hester, Caul, and Freya travel to Grimsby to save Wren, but upon arriving at the wrecked city, learn from Uncle that Wren is likely in Brighton. Uncle is killed, and Tom and Hester leave to find Wren, whilst Caul and Freya return to Anchorage with the remaining Lost Boys.
At Fang's command, the Green Storm armies extend their borders, starting a war with the Traktionstadtsgesellschaft, an alliance of German-speaking cities. Meanwhile, the Stalker Shrike is 're-resurrected' by Dr. Oenone Zero. Shrike hears Zero confide aloud that she will kill Fang with a mysterious weapon; Shrike prepares to kill her, but finds his programming prevents him from betraying her.