Heir of Fire is the third installment in Sarah J. Maas’s Throne of Glass series, which comprises seven books in total: Throne of Glass (2012), Crown of Midnight (2013), Heir of Fire (2014), Queen of Shadows (2015), Empire of Storms (2016), Tower of Dawn (2017), and Kingdom of Ash (2018). This high fantasy novel can be categorized as new adult fiction due to its graphic violence and adult themes, which include Redemption Through Self-Acceptance, Staying in Control, and Oppression Versus Freedom.

Throne of Glass is Mass’s debut series. Maas credits the tale of Cinderella as her inspiration for the series, with Celaena representing a destitute princess, although Maas’s story features a grittier tone and darker themes. It has received critical acclaim and been translated into 35 languages. Her other works include the A Court of Thorns and Roses new adult fantasy series and the Crescent City adult fantasy series.

This guide refers to the 2014 Kindle edition.

Content Warning: Heir of Fire contains scenes of explicit violence and depictions of grief and trauma.

Plot Summary

Heir of Fires follows three concurrent storylines conveyed through the perspectives of Celaena, Dorian, and Manon, respectively. It picks up after Crown of Midnight.

Celaena has been sent to Wendlyn on a mission for the king of Adarlan, but she decides to search for answers about the Wyrdkeys instead. The Wyrdkeys are ancient magical artifacts that control the gates to the Valg’s world, which the king wants to open to use their power. The Valg are dark, evil creatures that can inhabit and control a host’s mind.

While in Wendlyn, Celaena is found by Rowan Whitethorn, a Fae prince who serves Maeve, the immortal Fae queen and Celaena’s distant aunt. For years, she has searched for Celaena, who possesses a powerful ability to control fire. She agrees to answer the young girl’s question only if Celaena trains with Rowan to prove she is worthy of entering Doranelle, Maeve’s hidden Fae city.

Celaena and Rowan hate each other at first, but through their investigation of strange murders in the area, they find common ground in their shared grief and trauma. Their friendship is cemented when they fight together against three Valg princes and defeat them with Celaena’s fire magic.

Celaena slowly embraces her identity as Aelin, the lost queen of Terrasen, whom everyone presumed dead after the king had her parents murdered 10 years earlier. She eventually confronts Maeve, who reveals her own desire to get the Wyrdkeys, and forces her to break Rowan’s Blood Oath. He then swears his loyalty to Celaena. At the end of the book, the young girl decides to return to Adarlan to find the third Wyrdkey and raise an army against the king to reclaim her rightful throne and free the world from the Valg.

Meanwhile, in Adarlan, Dorian struggles to keep his magical powers hidden because his father has banned magic. He develops a romantic relationship with Sorscha, a healer who helps him conceal his powers. When he learns about Celaena’s true identity, Dorian remains loyal to their friendship and encourages Chaol to pick a side.

On the other hand, Chaol struggles to reconcile his loyalty to Dorian and his desire to rebel against the king’s cruelty. He enters an alliance with Aedion Ashryver, one of the king’s generals, who secretly works with the rebels while waiting for the return of his cousin, Aelin. Their investigations reveal how the king made magic disappear 10 years earlier. They plan to undo the spell and free magic again.

At the end of the book, the king forces Dorian to reveal his powers by executing Sorscha; the king then puts him under one of the Valg’s control. Before this, however, Dorian helps Chaol escape. The latter goes into hiding, vowing to fight against the king and free his friends, as Aedion is also taken prisoner.

A third main plot is introduced through Manon, heir of one of three deadly witch clans, and her loyal coven, the Thirteen. The king has promised the brutal and cruel Ironteeth witches wyverns in exchange for their service during the upcoming war. Manon, their greatest warrior, unexpectedly picks a small but cunning wyvern with whom she bonds.

Manon’s awareness of the cruelty and injustice of the Ironteeth witches develops throughout the story, culminating when she rebels against her grandmother and clan leader during the climactic War Games. Although she is crowned Wing Leader, it is a bittersweet victory that foreshadows her break from the Ironteeth witches in Queen of Shadows.