He was portrayed by Russell Harvard.
Mr. Wrench worked for the Fargo Crime Syndicate as a hitman and enforcer. He was often paired with Mr. Numbers due to his ability to translate Wrench's sign language. Following the murder of Sam Hess, Wrench and Numbers were sent to investigate and discover who commited the murder. Their search led them to Lenny Potts, a local man who bore resemblence to Lorne Malvo. They took Lenny captive but were told that he is not the man they're looking for. They then took him out to a frozen lake, where they dropped him into a hole in the ice.
Their search later leads them to Lester Nygaard, who had a known history of being bullied by Hess. They kidnap him and take him out to be dropped into the lake, but he tases Numbers and escapes. Lester gets away by punching a police officer who happened to be on a nearby road, forcing him to take him into custody and drive him into town. Wrench and Numbers then fake a drunken brawl in a bar in order to be locked into the drunk tank along with Lester.
While locked up, Wrench and Numbers interrogate Lester. They put pressure onto his infected hand wound and muffle his screams with a sock until he gives up Malvo's name. Wrench and Numbers are then bailed out of jail, presumably by the Syndicate. They also retrieve a police file on Malvo, giving them enough information to track him down.
They later find Malvo and ambush him during a whiteout. They get in front of and behind Malvo's car and trap him between their cars. Wrench gets out and fires his handgun at Malvo, but is knocked down when Malvo slams the car door into him. Wrench is later shot by Molly Solverson. Wrench is taken to the hospital to treat his gunshot wound. Molly interrogates Wrench in his room. Due to being handcuffed to his bed, Wrench is unable to use sign language so he communicates with Molly by writing on a white board on the wall. He asks Molly if Numbers is alive and reveals his deafness to her. Molly then asks Wrench if he and Numbers were looking for Lorne Malvo but he refuses to answer. Molly asks Wrench why Malvo tried to go after them, since Numbers died for the cause, and tells him that he will spend the rest of his life in jail. Wrench again refuses to answer and Molly leaves his room.
Later, Malvo enters Wrench's room and waits for him to wake up. When Wrench wakes up, Lorne reveals to him that he killed Numbers and the rest of the Fargo Crime Syndicate members. Wrench tries repeatedly to attack Malvo but fails due to being restrained. Malvo tells Wrench that both he and Numbers have come the closest to killing him. He then gives Wrench the keys to the handcuffs and tells Wrench to come find him again if he chooses to escape.