Kaz is the 17-year-old criminal mastermind of the Dregs, feared throughout Ketterdam's Barrel under the alias Dirtyhands. He is a ruthless and brilliant strategist who wears thick leather gloves and uses a crow-headed cane due to an improperly healed broken leg. Orphaned and swindled as a young child, he maintains a carefully guarded distance from others while devoting his life to a slow, methodical revenge against the men who ruined his family.

Inej is a 16-year-old Suli acrobat who serves as the Dregs' premier spy, known in the criminal underworld as the Wraith. As a survivor of human trafficking who was sold to a brothel before Kaz bought her indenture, she harbors a fierce ambition to hunt down slavers and dismantle the trade. She serves as the moral compass of the crew and finds strength in her religious devotion.

Jesper is a 17-year-old sharpshooter from Novyi Zem with a restless energy and a severe gambling addiction. He originally traveled to Ketterdam to attend university but quickly fell into debt and joined the Dregs. He secretly possesses Fabrikator Grisha abilities, which he hides due to childhood trauma and his father's warnings about the dangers of magic.

Wylan is the 16-year-old son of a wealthy merchant who fled to the city's criminal district after his father attempted to have him murdered. He serves as the Dregs' demolitions expert, creating chemical compounds and explosives. He harbors deep shame over his inability to read, an impairment that caused his father to disown him.

Nina is a 17-year-old Grisha Heartrender from Ravka. She is currently enduring severe withdrawal symptoms from jurda parem, a highly addictive chemical that has dangerously altered her traditional magic into something unpredictable. Despite her physical suffering, she maintains a loud, joyful presence and fights fiercely to protect her fellow Grisha from exploitation.

Matthias is an 18-year-old former drüskelle, a soldier specifically trained by the nation of Fjerda to hunt and execute Grisha. Disgraced and exiled, he now operates alongside the very criminals and magic-users he was raised to despise. He relies on his formal military training to keep the crew alive during combat, while internally working to unlearn the prejudices of his homeland.

Jan Van Eck is a wealthy, powerful member of the Kerch Merchant Council. He portrays himself as a respectable businessman but is entirely ruthless, willing to plunge the global economy into war by distributing a dangerous Grisha-enhancing drug. He considers the street gangs of Ketterdam to be disposable pests and severely underestimates Kaz Brekker's capacity for revenge.

Pekka Rollins is a Kaelish con man who rose to become the undisputed mob boss of the Ketterdam Barrel, leading the Dime Lions. Wealthy, physically imposing, and entirely ruthless, he partners with Van Eck to eliminate the Dregs. He remains largely unaware of the deep, personal trauma he inflicted upon Kaz years ago through a petty swindle.

Kuwei is the teenage Shu son of the scientist who created jurda parem. Following his father's death, Kuwei inherited the knowledge of the dangerous formula, making him the target of international assassins and governments. He possesses Inferni Grisha powers and relies entirely on Kaz's crew to smuggle him to safety in Ravka.

Colm is a hardworking jurda farmer from Novyi Zem. He arrives in Ketterdam believing his son is an honest university student, only to discover that his farm has been leveraged to pay off massive gambling debts. Despite his initial shock, he proves resourceful and steps in to assist the teenage gang in a high-stakes con.

Dunyasha is a highly lethal assassin known as the White Blade. Hired by Pekka Rollins to eliminate the Wraith, she views her contract killings as a sacred duty rather than mere criminal work. She claims to possess royal Ravkan blood and acts as a dark reflection of Inej's own lethal capabilities.

Zoya is an incredibly powerful Ravkan Squaller working to safely extract vulnerable Grisha from Ketterdam before they can be weaponized. She operates with absolute authority among her people and maintains a deep suspicion of any outsiders, particularly Fjerdan soldiers.

Genya is a highly skilled Ravkan Tailor, a Grisha capable of altering a person's physical appearance. She travels to Ketterdam to assist in rescuing Grisha refugees and offers her unique magical talents to help the Dregs pull off their elaborate disguises.

Alys is Jan Van Eck's young, pregnant wife. She is largely naive to the dark realities of Ketterdam and her husband's violent business practices. When frightened or anxious, she copes by singing constantly.

Smeet is Jan Van Eck's personal lawyer and property manager. He represents the bureaucratic side of Ketterdam's corruption, carrying out cruel evictions and legal maneuvers while considering himself a respectable citizen.

Sturmhond is a legendary and flamboyant privateer who operates closely with the Ravkan Grisha. He possesses immense wealth and naval resources, making him a crucial backer for Kaz's ambitious auction scheme.

Per Haskell is the aging, nominal leader of the Dregs gang. While he holds the official title, he relies entirely on Kaz to generate revenue and maintain the gang's fearsome reputation, preferring a comfortable, hands-off approach to leadership.

Jordie is Kaz's older brother who died of firepox years ago. Following their father's death, Jordie brought young Kaz to Ketterdam, where the naive boys were swindled out of their inheritance. Jordie's tragic death forged Kaz into the ruthless criminal he is today.

Alby is the young son of crime boss Pekka Rollins. He is heavily guarded and kept safely away from his father's criminal enterprises in a country estate. He represents his father's only true vulnerability.

Emil is a Ravkan Squaller working off an indenture for the Kerch Merchant Council. He dreams of returning to his homeland but is abruptly abducted by mechanically enhanced soldiers, serving as an early example of the dangers Grisha face in the city.