Clockwork Princess recap

Tessa Gray and Jem Carstairs plan their wedding while Axel Mortmain quietly buys up the drug keeping Jem alive, and Benedict Lightwood's demon pox turns him into a monster his own sons must destroy. Mortmain's agents reach into the Institute, Jessamine Lovelace is killed, and Tessa is carried off to his stronghold beneath the Welsh mountain Cadair Idris. Will Herondale rides for Wales alone and the household follows; Jem, out of his drug and dying, is left behind, and during the pursuit Will feels their parabatai bond break. Mortmain tells Tessa what she is: the deliberately engineered child of a Shadowhunter mother and a Greater Demon that took the body of her mother's husband, made shapeshifter, fertile, and unmarked, to be his bride and the mother of a new race. Cornered, Tessa takes the shape of the angel bound inside her mother's clockwork pendant and destroys Mortmain and his automaton army. Jem is not dead; he survived by becoming a Silent Brother. Will and Tessa marry and have children, Will dies of old age with both of them beside him, and the story ends more than a century later with Tessa and Jem meeting on Blackfriars Bridge.

Previously in The Infernal Devices: Tessa Gray came from New York to London in 1878, was imprisoned by two warlocks who forced her to discover that she can Change into anyone whose possession she holds, and was rescued by Will Herondale of the London Institute. She has lived there since, among Charlotte and Henry Branwell, the maid Sophie, Jessamine Lovelace and Will's parabatai Jem Carstairs, who is kept alive and slowly killed by a demon drug. Her brother Nate betrayed her and the Institute to Axel Mortmain, a mundane inventor with an army of clockwork automatons who wants Tessa for reasons of his own; Nate died of his injuries in Tessa's arms. Mortmain was raised by warlocks killed in a Shadowhunter raid and has spent his life preparing revenge on the Nephilim, and he escaped both attempts to take him, with a stolen box of bound demon energies. Charlotte kept the Institute against Benedict Lightwood's challenge after his demon pox and his payments from Mortmain came to light, and after discovering that the Consul himself had been Mortmain's informant. Will learned that the demon who told him as a child that everyone who loved him would die had lied, freeing him five years too late: Tessa had just accepted a proposal from the dying Jem, and Will said nothing. Will's sister Cecily arrived at the Institute demanding to be trained.

Tessa and Jem are engaged and their wedding is being arranged, but the drug that keeps Jem alive has become impossible to buy: Mortmain has been quietly acquiring the entire supply, so that Jem's death is now a matter of weeks and is in Mortmain's gift. Will, who says nothing about his own feelings, spends his time hunting for a source anywhere in Britain. Cecily Herondale is training at the Institute and still trying to make her brother come home to Wales; Gideon Lightwood is living there too, close to Sophie; Gabriel remains at the family house, where Benedict has shut himself away, refuses to be seen, and is behaving in ways his sons cannot explain. Charlotte, expecting a child, runs the Institute and its search knowing that the Clave's own leadership has been compromised. Nobody has found Mortmain, who has no fixed address, several false names, and the ability to reach the Institute's household without being seen.

Gabriel arrives at the Institute for help: his father's demon pox has run its course and Benedict Lightwood is no longer a man but a monstrous creature loose on the family estate. The Shadowhunters go to the house and destroy it, and both Lightwood brothers move into the Institute for good, their family name in ruins. Jessamine Lovelace is released from the Silent City into the Institute's custody, frightened and much reduced, kept apart from the household and trusted by no one. The Institute's defences are tested by Mortmain's automatons, which are better made than the ones the Shadowhunters have fought before, and it becomes plain that what Mortmain wants in exchange for leaving them alone is Tessa herself. Charlotte refuses to consider it. Jem's condition continues to worsen, and the wedding is brought forward against the certainty that time is running out.

Mortmain reaches inside the Institute. Jessamine, manipulated and coerced, is used to get his creatures past its protections, and she is killed for what she does or fails to do; the household finds her too late to save her. In the same stroke Tessa is taken out of the Institute and carried away, and every search the Shadowhunters mount for her fails, because Mortmain's stronghold is not in London and is not on any map the Clave holds. Jem, out of the drug that sustains him and told that Tessa is gone, deteriorates sharply. The Institute pieces together, from Mortmain's history, his properties and the fragments Nate and Jessamine left behind, that the place they are looking for is in Wales, under the mountain Cadair Idris.

Will rides for Wales alone the moment the location is known, refusing to wait for the Clave and riding almost without rest. Jem, too ill to follow, is left in the Institute's care as the last of his drug runs out; the Silent Brothers take him, and the household expects him to die. Charlotte, Henry, Cecily, Gideon, Gabriel and Sophie follow Will west with what weapons Henry can devise. In Mortmain's stronghold beneath the mountain, Tessa is held in comfort and dressed for a wedding: Mortmain intends to marry her, and he has a use for her that goes beyond the marriage. He begins to tell her, in pieces, what she is and why she exists, and it becomes clear that her ability to Change and her lack of a warlock's mark were designed rather than accidental.

Mortmain gives Tessa the whole of it. Her birth was engineered: her mother was of Shadowhunter blood, and her father was a Greater Demon that Mortmain summoned into the body of her mother's husband, so that the child would be a shapeshifter without a warlock's mark and, unlike a warlock, able to bear children. She was made to be his bride and the beginning of a race of his own, and her brother Nate, an ordinary human child of the same marriage, was never any relation to that plan. On the road west Will feels the parabatai bond tear, and believes Jem has died. He reaches the mountain ahead of the others and gets to Tessa, and the two of them, grieving Jem and expecting to die there, admit to each other what neither has said. Mortmain's automaton army is assembled beneath Cadair Idris, and the handful of Shadowhunters converging on the mountain have no realistic chance against it.

The battle at Cadair Idris goes badly: the Shadowhunters are hopelessly outnumbered by the automatons, and Henry is struck down and crippled, losing the use of his legs. Cornered by Mortmain, Tessa finally learns what the clockwork angel her mother left her actually is. An angel, Ithuriel, is bound inside it, and its life has been keeping her alive and healing her injuries since she was born. Tessa takes the angel's own shape, the one form she has never been able to hold, and its power destroys Mortmain and burns out the mechanical army with him. The angel is freed and the pendant falls silent. The threat that has shaped all three books ends there, at the cost of Henry's legs, of Jessamine's life, and, as far as anyone at the mountain knows, of Jem's.

Jem did not die. Dying and beyond the drug's help, he was taken by the Silent Brothers and survived the transformation into one of them; he returns as Brother Zachariah, unable to marry Tessa or to live as James Carstairs, but alive and still himself enough to release them both. Will and Tessa marry with his blessing and have two children, James and Lucie. Charlotte becomes Consul; Sophie Ascends to Shadowhunter and marries Gideon; Cecily marries Gabriel; Henry works from a wheelchair for the rest of his life. Will lives to be an old man, and dies with Tessa and Jem beside him. Tessa, who does not age, outlives her husband, her friends and eventually her children. The book closes more than a century later, in the present day, on Blackfriars Bridge in London, where Tessa keeps the appointment she and Jem have kept once a year for decades: he is still a Silent Brother, she is still waiting, and the two of them go on meeting there in the hope that will one day change.

Cornered in Mortmain's stronghold beneath Cadair Idris, Tessa discovers what her mother's clockwork angel is: an angel, Ithuriel, bound inside it, whose life has been sustaining and healing her since birth. She takes the angel's own shape and uses its power to destroy Mortmain and burn out his automaton army, ending the threat and freeing the angel. Henry is crippled in the battle and will not walk again, and the parabatai bond between Will and Jem breaks during the fight. Jem is not dead: dying and out of the drug that sustained him, he was taken by the Silent Brothers and survived the transformation into one of them, and he returns as Brother Zachariah, no longer able to marry Tessa or to live as James Carstairs. Will and Tessa, who turned to each other in grief, marry with Jem's blessing and have two children, James and Lucie. Charlotte becomes Consul; Sophie Ascends and marries Gideon; Cecily marries Gabriel. Will lives a full life and dies an old man with Tessa and Jem beside him, and Tessa, who does not age, outlives them all. The book closes in the present day on Blackfriars Bridge, where Tessa keeps a standing appointment with Jem, still a Silent Brother, once a year, and where the two of them are still waiting for a change that might one day give them back to each other.