Zack Addy

The episode "The Perfect Pieces in the Purple Pond" reveals Addy is receiving psychological treatment from FBI psychologist Dr. Lance Sweets. Later in the episode, returning to the asylum from which he escaped, he tells Sweets that although he helped Gormogon find the lobbyist, he himself had not actually stabbed him. Sweets insists he has to change his story, but Addy refuses to do so. He fears that if his secret were to be revealed, he would end up in prison where he would suffer.

In the Season 4 finale, Zack Addy is considered a suspect when a man is murdered in a popular nightclub owned by Booth and Brennan. At the end of the episode, it is revealed that the entire thing was in fact a dream about an alternate timeline that Booth had while being unconscious and is the part of a new book Brennan was writing.

Zack Addy returns in the 100th episode as a flashback to Booth and Brennan's first case together.

The last two episodes in season 11 introduce a serial killer named The Puppeteer, due to the nature of the crimes and how the killer would hang the victims from wires and use them as puppets.^[3] Over the past few weeks, Dr. Brennan has been having vivid nightmares and seeks a therapist's help to interpret her dreams. The therapist makes Brennan realize that the attacker in her dreams is someone she knows. The team goes over all the clues about the puppeteer and realize that they point to Zack Addy.

The Season 12 premiere of Bones reveals that Addy has taken Brennan to the old vault of the Gormogon, which is in the basement of the Jeffersonian, with the intention of protecting her from The Puppeteer and to reveal the truth about himself. Booth captures him, and he is taken into custody. After the death of Lance Sweets, Addy harmed himself in a fit of devastation, leaving occasional blackouts from minor brain damage. Addy consults the evidence files on the puppeteer case and concludes that he committed the crimes while blacked out and wishes to return to the mental institution. The team at the Jeffersonian finds out that it is instead Addy’s doctor from the institution, Dr. Mihir Roshan, who has been committing the murders and arranging the skeleton marionettes.^[4] Dr. Roshan intended to poison Addy, but Booth arrives at the institution in time to save him by shooting Roshan. Unable to kill Roshan himself, Addy concludes he could not have committed murder under the order of the Gormogon, and confesses his innocence to Brennan and Booth.^[5]

In "The Steal on the Wheels," the Jeffersonian team is able to locate the body of the Gormogon's former apprentice, the true killer, and match the blood on it to the lobbyist Addy supposedly killed. In "The Day in the Life," Addy goes before a judge for his appeal. Based on this new evidence, Zack Addy is acquitted of the murder charge, but not of aiding a known killer. As a result, he will have to finish the remaining thirteen months of his sentence, a result Addy readily accepts.

Despite his sharp mind, Zack grapples with uncertainty, particularly evident in his hesitation to assert himself, especially with Dr. Brennan. This dynamic is thoughtfully explored, potentially influenced by an undercurrent of romantic feelings for his colleague. When he discovered Dr. Brennan's own Forensic Anthropology professor had become her lover, Zack repeatedly wondered aloud whether he might enter into a similar relationship with Dr. Brennan.^[6] Zack's romantic entanglements, notably with "Naomi in Paleontology," offer a glimpse into the complexities of modern relationships. The on-and-off nature of their connection is a reflection of the intricacies that often accompany personal connections in the real world.^[7]

After the reveal that the character of Zack Addy was working with the Gormogon, Addy was no longer a regular character on the show. Series creator Hart Hanson had said he may become a recurring character to provide consults to the team with "certain talents we can use in a 'Hannibal Lecter' kind of way."^[8]

Outside the laboratory, Addy struggles with social interaction and