Kaz Brekker
Kaz Brekker, aka Dirtyhands, is a 17-year-old thief and criminal mastermind. He is the de facto leader of the Dregs, and he assembles the crew to free Bo Yul-Bayur from the Ice Court. He has strong feelings for Inej Ghafa. He walks with a cane and always wears gloves because he can't stand the feeling of human flesh. His goal is to get revenge on Pekka Rollins for scamming him and killing his brother, ideally getting rich in the progress.
Inej Ghafa
Inej Ghafa, aka the Wraith, is a member of Kaz's heist crew. She was stolen from her Suli caravan and sold to the Menagerie, a race-fetish pleasure house, before her indenture was bought by the Dregs. She has strong feelings for Kaz Brekker. She is an excellent spy, thanks to her training as an acrobat, and is known for performing impossible feats of agility and stealth. Her initial goal is to make enough money to pay off her indenture and return to Ravka to look for her family, but by the end of the book she decides to buy a ship and fight slavers like the ones who took her.
Jesper Fahey
Jesper Fahey is a Kaelish-Zemeni sharpshooter and member of the Dregs. He has a gambling addiction, fed by a loan his father took out against the family farm to pay for Jesper to go to university. Jesper loves shootouts and risk, and he is secretly an untrained Grisha Fabrikator. He and Wylan develop a teasing flirtatious relationship.
Nina Zenik
Nina Zenik is a Ravkan Grisha Heartrender who works with the Dregs as she tries to save Matthias Helvar from prison (where she inadvertently put him). She was captured by drüskelle and shipwrecked with Matthias, and now she sells her Grisha services out of a brothel in Ketterdam. She is strong and unapologetic, enjoying the finer things in life, and she intends to return to Ravka once Matthias is free. She has strong feelings for Matthias that develop into romance.
Matthias Helvar
Matthias Helvar is a Fjerdan drüskelle, a Grisha-hunter, recruited by Kaz because of his knowledge of the Ice Court. He has been stuck in a Kerch prison because Nina falsely identified him as a slaver to save his life after they were shipwrecked together. Matthias is serious and fiercely loyal to his country. His initial goal is to get his freedom by helping the heist crew, then kill Nina, Bo Yul-Bayur, and Kaz; as his bitterness toward Nina fades, the two develop a romantic connection, and Matthias betrays Fjerda to help the crew complete the mission.
Wylan Van Eck
Wylan is the intelligent, sensitive son of Jan Van Eck, brought onto the crew for his demolition skills plus his value as collateral. He is book-smart, shy, and naive about the ways of the world, but he and Jesper develop a teasing flirtatious relationship. Wylan ran away from home because his father essentially disowned him for being unable to read.
Jan Van Eck
Jan Van Eck is a wealthy Ketterdam merchant. He hires Kaz to rescue Bo Yul-Bayur, posing as the Merchant Council while secretly acting in his own interest. He is ruthless, intelligent, and obsessed with profit.
Per Haskell
Per Haskell is the leader of the Dregs, and he incorrectly considers the gang's improvement his doing rather than Kaz's. He is out of touch with the ruthless way the Barrel works nowadays.
Pekka Rollins
Pekka Rollins is the head of the Dime Lions, the strongest gang in Ketterdam. Rollins scammed Kaz and his brother out of their money when they were children, and Kaz's goal in life is to tear Rollins's life apart brick by brick. Rollins is also hired to steal Bo Yul-Bayur from the Ice Court, but his crew is killed and he is stuck in a cell, then freed by Kaz, who wants to be the one to kill him. The final chapter in the book is from Rollins's perspective, when he gives the crew money to take down Van Eck.
Jarl Brum
Jarl Brum is captain of the drüskelle and Matthias's father-figure. Brum led the expedition that captured Nina. Brum is clever and ruthless, and Matthias learns that his dedication to Fjerda is actually just a love of hurting Grisha.
Joost, Anya, and Hoede
Joost is the narrator of the first chapter of the book, a young stadwatch guard who witnesses the power of jurda parem. Hoede, a Ketterdam merchant, has been testing parem on his indentured Grisha, including Anya, a Grisha Healer. When Anya is given parem, she commands Joost to "wait," which he does until he eventually dies, and commands Hoede to cut off his own thumb. These experiments with parem inspire Van Eck to hire Kaz Brekker to free Bo Yul-Bayur.
Heleen Van Houden
Heleen owns and runs the Menagerie, a pleasure house in Ketterdam that capitalizes on race fetishes (for example, Inej is bought for her dark skin, then forced to wear traditional Suli silks/bells on her ankles). Heleen is a beautiful and vain woman, particularly vindictive against Inej, who she swears will wear her silks again.
Bo Yul-Bayur
Bo Yul-Bayur is the Shu scientist who developed jurda parem, then was imprisoned by the Fjerdan government and sought after by many other governments and groups. It is revealed the Yul-Bayur is dead, survived by his son Kuwei; he and Kuwei are both Grisha, and he made parem by accident while looking for a drug that would help them hide their powers.
Kuwei Yul-Bo
Kuwei Yul-Bo is Bo Yul-Bayur's teenage son, kept prisoner by the Fjerdan government after his father's death. He can replicate the jurda parem formula, though he has done his best to stall the Fjerdans and lead them in the wrong direction. The crew saves Kuwei from the Ice Court and takes him to Ketterdam.
Jordie Rietveld
Jordie Rietveld was Kaz's older brother. Jordie was hardworking and kind, but a bit too idealistic—an easy mark. After Pekka Rollins scammed them out of everything they own, Jordie became homeless and died of firepox. Kaz used his corpse as a raft to swim back to Ketterdam, and since then he can't stand the feel of human flesh.
Geels and Oomen
Geels is the leader of the Black Tips, a Ketterdam gang, and Oomen is his right-hand man. Kaz meets with Geels at the beginning of the novel and outsmarts him; when Oomen attacks Inej, Kaz cuts his eye out, then throws him overboard.
Big Bollinger
Big Bollinger is a member of the Dregs who is selling information to the Black Tips. In his meeting with Geels, Kaz has Big Bollinger shot, displaying his ruthlessness and his tendency to keep his plans close to his chest.
