Clockwork Princess — The Infernal Devices, Book 3

Clockwork Princess Review

The question any reader brings to Clockwork Princess is simple and apparently impossible: how does Cassandra Clare resolve a love triangle in which both men are genuinely, equally deserving? The answer she found is one of the most discussed endings in contemporary young adult fiction, and discussing it freely would rob new readers of the experience of being surprised by something that in retrospect feels entirely inevitable.

What can be said is this: Clare does not choose the easy answer, the cruel answer, or the convenient answer. She finds a third path that honours the full depth of what Tessa, Will, and Jem mean to each other, and she earns it through two novels of meticulous emotional preparation.

The external plot of Clockwork Princess is the series’ most ambitious. Mortmain’s clockwork army goes to war against every Shadowhunter alive, and the battle sequences Clare constructs are genuinely cinematic — full-scale conflicts with real casualties among characters the reader has spent three books caring about. The stakes feel earned rather than inflated, and Clare does not flinch from the cost.

But it is the personal resolution that the novel will be remembered for. Jem’s transformation — the circumstances that change what he is and what he can be — is handled with a precision that makes the impossible feel logical. Will’s grief and love and eventual peace are rendered with a tenderness Clare has been building toward since the first chapter of Clockwork Angel. Tessa’s choice, and the enormity of what she gives and receives, carries the full weight of everything that has come before.

The epilogue, set decades later, is among the most emotionally generous endings in the genre. It rewards patience and commitment with an answer that genuinely satisfies.

Our rating: 4.8/5 — A rare series conclusion that delivers on every promise made across three books, and resolves its central dilemma with both intelligence and heart.

Reading Order

1. Clockwork Angel (The Infernal Devices, Book 1)
2. Clockwork Prince (The Infernal Devices, Book 2)
3. Clockwork Princess (The Infernal Devices, Book 3)

Reading Guides

• Cassandra Clare Books in Order: Complete Shadowhunters Reading Guide (2026)

The Third Path

Cassandra Clare faced a structural problem that most authors of love triangles never attempt to solve: both Will Herondale and Jem Carstairs are fully deserving. The genre convention for triangles is that one of the two parties is the real choice — the genuine romantic lead whose superiority the protagonist has been failing to recognise — while the other is the false choice, attractive and sympathetic but ultimately less suited to the heroine’s needs. The Infernal Devices refuses this convention from the beginning.

Jem is not a consolation prize. His gentleness and his musicality and his specific kind of courage — the courage of someone who knows he is dying and chooses to live fully anyway — are qualities that deserve what Tessa feels for him. Will is not the obvious choice held back by misunderstanding; his darkness is real, its origins are tragic, and the person he is without the curse’s constraints is genuinely worth loving.

The solution Clare found — which this review will not spoil — requires a supernatural mechanism that some readers have objected to as convenient. The objection is fair on its face; what makes it insufficient is that the solution was prepared in the mythology from the beginning of the series. The specific nature of what happens to Jem, and why it is possible, connects to information introduced in Clockwork Angel with enough specificity that the resolution feels like the discovery of something that was always true rather than the invention of something new.

The Epilogue

The epilogue of Clockwork Princess is among the most discussed endings in contemporary young adult fiction, and the reason is temporal. Clare does not end the series at the moment of resolution; she ends it decades later, showing what the lives of the characters look like after the crisis has passed and time has done its work. The effect is cumulative: the reader who has spent three books caring about these characters is given not the climax but the aftermath, the ordinary joy and ordinary grief and the long shape of lives lived beyond the story’s dramatic peak.

This is a rarer and more generous ending than the genre typically provides.

Will Herondale

Will’s arc across the Infernal Devices trilogy is one of the Shadowhunter Chronicles’ finest extended character studies. The young man introduced in Clockwork Angel as the darker and more volatile of the two parabatai — beautiful, cruel, and clearly concealing something — arrives at the end of Clockwork Princess as someone whose full humanity is visible, whose capacity for love and friendship and ordinary life has been recovered from under years of deliberate self-destruction.

Clare handles the transition without making it miraculous. Will does not transform; he recovers. The person he was always capable of being was always there; what changed was his belief in whether he was allowed to be that person.

The Infernal Devices and the Shadowhunter Legacy

Clockwork Princess was published in March 2013 and debuted at number one on the New York Times bestseller list. More enduringly, it cemented The Infernal Devices’ reputation as the Shadowhunter Chronicles’ finest trilogy — a consensus that has held across more than a decade of new series, additional trilogies, and continued expansion of the Shadowhunter world. The Victorian setting, the three-way love story, and the epilogue’s emotional generosity have made it the standard against which everything Clare has written since is measured.