Plot Summary

Kaz Brekker, the leader of a gang called the Dregs, is offered a lucrative job to break into a nearly impenetrable prison in Fjerda to kidnap a Shu scientist called Bo Yul-Bayur. Bo Yul-Bayur was being held captive by the Fjerdan for creating a mixture based of a street drug called Jurda. The concoction, Jurda Parem, is highly addictive and enhances the magical abilities of Grisha to dangerous measures. Kaz negotiates on a large sum of money to receive for his job and sets together a crew consisting of other gang members- Inej, Nina, Jesper, Matthias, and Wylan, each with a unique skill.

The crew plan their route and set aboard the Ferolind to head for Fjerda. After fighting through a few attacks, they reach Fjerda and trek to the Ice Castle where the prison is located. A ceremony called Hringkalla causes there to be a huge party in the castle, and they are miraculously able to make their way into the castle disguised as prisoners. After a series of events causing them to change their plan, they are finally able to locate where Yul-Bayur was being kept. They discover that Yul-Bayur was already dead, and instead his son was being kept captive and forced to recreate Jurda Parem. The crew rescue the son and head out of the castle where they find themselves surrounded by the Fjerdan army. Nina, a Grisha herself, ingests Jurda Parem and defeats the army with her heightened powers, and the crew board the Ferolind back to Ketterdam.

When the crew meets Van Eck on a deserted island to demand their prize, he double crosses them and tries to kill them. They realize that Van Eck had planned to use Yul-Bayur’s recipe to make profit for himself, not keep it safely hidden away from the world as he had promised. Van Eck is able to escape from the island, and the novel concludes with Kaz vowing to teach him a lesson, leading to the sequel.