Clockwork Prince is the second book in Cassandra Clare’s “The Infernal Devices” trilogy.
The book starts with Tessa Gray still living in the London Institute with the other Shadowhunters.
She’s recently had her whole world tipped upside down as she discovered that much about her life had been a lie and that she could change her form into anyone—Having access to their memories and mannerisms in the process—.
After the events of the previous book, Charlotte Branwell, accompanied by her husband Henry, Tessa Gray, Will Herondale, Jem Carstairs, and Jessamine Lovelace, are summoned to a Shadowhunters’ Council assembly.
Their purpose: to provide testimony concerning Charlotte’s perceived failure in apprehending Axel Mortmain, the elusive leader of the Pandemonium Club.
Amongst the council members, Benedict Lightwood, harboring animosity towards Granville Fairchild, Charlotte’s father, manipulates Consul Wayland into issuing an ultimatum to Charlotte.
She is given only a two-week time period to capture Mortmain, or face the dire consequence of resigning as head of the London Institute.
To bolster the Institute’s defenses, the Lightwood patriarch further orchestrates the appointment of his sons, Gideon and Gabriel, as instructors in self-defense. Their charge? To train Tessa, Jessamine, and Sophie Collins, securing their combat skills.
However, complications arise when Jessamine adamantly refuses to participate in the training regimen, adding tension to the already strained atmosphere within the Institute.
On a strict deadline, the entire Institute immediately launches an intense search for Mortmain, uncovering unsettling details about his origins.
They learn that Mortmain’s adoptive warlock parents, John Shade and Anne, were slain by the Clave before the signing of the Accords.
Charlotte speculates that Mortmain’s vendetta against the Clave stems from his failed attempt to seek Reparations for their deaths.
To gather more information, Tessa, Will, and Jem are dispatched to interrogate Aloysius Starkweather from the York Institute, the Shadowhunter responsible for executing Shade.
While in York, Will makes a startling discovery about his own family’s involvement with Mortmain.
He learns that his sister Cecily and his parents are residing in Ravenscar Manor, a property owned by Mortmain. The situation takes a dangerous turn when the trio is ambushed by one of Mortmain’s automatons, which delivers a chilling warning to Will, threatening harm to his loved ones if he interferes.
In the ensuing chaos, Tessa narrowly escapes death thanks to her clockwork angel, which unexpectedly springs to her defense. This encounter adds urgency to their mission and underscores the dangerous nature of their pursuit.
After their fruitless return to London, Will confides in Magnus Bane— Whom he had been working with from the ending of the first book unknown to anyone else— about his troubled past.
He reveals that he fled his home and distanced himself emotionally from others to escape a curse inadvertently unleashed by a demon imprisoned in his father’s Pyxis box.
This curse preys on those who care for him, beginning with his sister, Ella. Desperate for a solution, Will begs Magnus to summon the demon.
As Will’s mental health deteriorates, he withdraws further, neglecting to return home, prompting Magnus to send a letter to Tessa urging her to search for him.
Tessa and Jem embark on a search and eventually locate a drugged Will in an ifrit den, where they rescue him and bring him home.
Amidst the turmoil, Tessa provides solace to Jem, who is grappling with his own frustrations.
In a charged moment of vulnerability, Jem nearly confesses his feelings for Tessa, but they both choose to remain silent, each nursing their own emotional wounds.
The following day, Will reveals during breakfast that he has uncovered information linking werewolves to the drug yin fen, which Jem relies on for survival.
Charlotte, sensing a connection to Mortmain’s machinations, seeks answers from Woolsey Scott, the leader of London’s werewolf pack, but receives a dismissive response.
This leads Charlotte to suspect that Mortmain may have enlisted rogue werewolves to aid in his sinister plans involving the automatons.
During their training sessions, Gideon forms a strong bond with Sophie, eventually confiding in Tessa about the deep-rooted animosity between Benedict and the Fairchilds.
He discloses that Benedict’s uncle Silas tragically ended his life following the revelation of his forbidden relationship with his parabatai, a revelation spurred by Granville Fairchild.
This devastating event led to the despair-driven death of Silas’s mother, Barbara. Meanwhile, Sophie shares with Tessa a startling revelation: Jessamine is secretly involved with her brother, Nate, who has invited her to a ball hosted at the Lightwood manor.
Taking matters into her own hands, Sophie incapacitates Jessamine and procures the invitation, allowing Tessa to attend the ball in disguise.
Accompanied by Will, Tessa infiltrates the event and makes a shocking discovery: Benedict is entangled in a demonic relationship and is colluding with Mortmain and Nate to undermine Charlotte’s authority.
Amidst the chaos, Will and Tessa are interrupted by Magnus, who reveals that their drinks were laced with warlock powder.
As tensions escalate, Will spots Marbas, the demon responsible for his cursed past, and gives chase.
Charlotte calls upon the Silent Brothers to apprehend Jessamine, subjecting her to interrogation with the Mortal Sword before incarcerating her in the Silent City.
Seeking reconciliation, Tessa and Jem visit Jessamine in her cell, persuading her to betray Nate by arranging a rendezvous.
However, Nate anticipates their scheme and arrives with an automaton to level the playing field.
During the confrontation, Nate reveals a shocking truth to Tessa: they are cousins, his true mother being Aunt Harriet, who concealed his illegitimate birth by passing him off as Elizabeth’s son.
In a tense showdown, Tessa outwits the automaton, causing it to turn on Nate, fatally injuring him. Tragically, Will sustains severe wounds in the process.
In his dying moments, Nate expresses remorse to Tessa and implores her to always wear her angel pendant.
Following Will’s recovery, he seeks out Magnus, who has parted ways with Camille Belcourt and is now residing with Woolsey, to confront Marbas.
However, Will is stunned when Marbas reveals that there was never any curse; Ella’s demise was the result of being poisoned while defending Will.
This revelation shatters Will’s understanding of his past and sets him on a path of profound introspection and reevaluation.
Just days before the deadline to apprehend Mortmain, Sophie shares crucial information with Charlotte, gleaned from Gideon, shedding light on the true circumstances surrounding his mother and uncle’s deaths.
Barbara Lightwood’s demise was a result of contracting demon pox from Benedict, leading her to take her own life. Contrary to previous beliefs, Silas’s suicide was unrelated to any actions by the Fairchilds.
Leveraging this newfound knowledge, Charlotte coerces Benedict into withdrawing his challenge, yet Gideon pays the price for his honesty, being ousted from the Lightwood estate and seeking refuge within the confines of the London Institute.
Meanwhile, amidst the mounting tension, Will finally lays bare his feelings for Tessa, only to be met with the revelation that she has accepted Jem’s proposal of marriage.
Their engagement is announced amidst the jubilation of Charlotte’s vindication, with the additional surprise of Charlotte’s pregnancy.
However, the festivities are interrupted by the unexpected arrival of Cecily Herondale, who demands training as a Shadowhunter, throwing yet another curveball into the already tumultuous affairs of the Institute.
As the dust settles on one set of revelations, new challenges emerge, promising further twists and turns in the intricate tapestry of their lives.
