|Last appearance||"The Parts in the Sum of the Whole" (flashback)|
|Created by||Hart Hanson|
|Portrayed by||Eric Millegan|
|Nickname(s)||Zackaroni, Zacko, King of the Lab/King of the Loony-bin, Z-Man.|
|Family||3 brothers, 4 sisters|
|Religion||Rational Empiricist (Raised Lutheran)|
Zachary Uriah "Zack" Addy, Ph.D, is a fictional character in the television series Bones. He is portrayed by Eric Millegan. The character was introduced as Dr. Temperance Brennan's brilliant young assistant at the beginning of the series before he received his doctorate in Forensic Anthropology in Season 2. Millegan was a series regular for Seasons 1-3, appearing in all episodes. Since then, he has made three guest appearances in Season 4's "The Perfect Pieces in the Purple Pond" and "The End in the Beginning" (dream sequence) and Season 5's "The Parts in the Sum of the Whole" (flashback).
The youngest in a large Michigan family with three brothers and four sisters, Zack was a child prodigy, a genius with an I.Q. well above 163 with a supposed eidetic memory. According to his character bio on the DVD for Season 1, Zack graduated college at the age of 16. It is revealed in the episode "The Boy in the Time Capsule" that Zack was physically bullied harshly all through high school by other boys. In "A Boy in a Tree," he is heard saying he "didn't have any friends" all through high school and endured relentless physical and emotional abuse all through his school life. Additionally, it is revealed that Zack is an excellent singer. At the beginning of the show, he had started two doctorates—one in Forensic Anthropology, the completion of which is shown on-screen in the episode "Judas on a Pole", the other in Applied Engineering, the completion of which is referred to in "The Killer in the Concrete".
His specialty, just like Dr. Brennan, is in the analysis of remains, especially identifying cause of death and weapons from marks on skeletal remains. It is usually his task to remove the flesh from the bones, a process known as maceration. Because of his tremendous intellect, he has a strong broad-based knowledge of many of the specialties in the Jeffersonian lab.
Zack's best friend is Jack Hodgins. Although it at first appears Hodgins and Zack are roommates, it is later revealed he rents the apartment over Hodgins' garage. Zack also carpools with Hodgins because he can neither drive a car nor ride a bike. He once made a comment to Booth that, if Booth shared Zack's knowledge of Structural Engineering, he would be afraid to drive as well (Season 1 "The Man on Death Row"). In The Man in the Bear, Zack and Hodgins compete for the affections of a beautiful delivery lady until they realize in the end that she might be bisexual or homosexual, when she shows an attraction to forensic artist Angela Montenegro.
Episodes towards the end of Season 1 reveal Zack's colleagues, especially Dr. Goodman, feel he has become too comfortable as Dr. Brennan's assistant and is therefore not completing any of his work towards his doctorate degrees to avoid having to move into a new position. Goodman and Hodgins conspire to make Zack less comfortable in his position to motivate him to complete his studies, thus encouraging him to fulfill his potential of more than just an assistant.
Right before he was about to complete his doctorate, Zack asks the Jeffersonian's new forensics head, Dr. Camille Saroyan, if he can have a job working at the Jeffersonian. She replies she could not put him in front of a court to testify because people would not take him seriously. Zack then goes to ask Angela for fashion advice, and she gives him a complete makeover that includes a new haircut and a suit. After completing his doctorate and getting the makeover from Angela, Zack again asks Cam for a job; and she gives it to him, saying "Who am I to break up the team?"
At the end of Season 2, Zack receives a request from the office of the President to ship out to Iraq. What his duties there would be is not revealed, and he only tells Hodgins and Booth about it. He is indecisive and asks Booth for advice as Booth "knows more about duty and honor than anyone else I know". Zack also turns down the offer to be the Best Man at Hodgins and Angela's wedding in case he decides to go to Iraq and is killed, because he does not want Hodgins' memories of the wedding to be tainted with sadness, but Zack is later seen at the wedding. It is revealed in Episode 1 of Season 3 that Zack had just returned from a three-month stint in Iraq, having returned early because he "failed to assimilate."
In "The Pain in the Heart", the final episode of Season 3, Zack receives third-degree burns and massive tissue damage on both hands after an explosion in the lab. It is later revealed he was working as the apprentice of the Gormogon, even though he is not the son of a widow, and the explosion was designed as a distraction so Gormogon could break into the lab and steal back the silver skeleton. Zack's weaker personality was easily manipulated by Gormogon so he believed his belief system irrefutable, even going as far as to divide the bones of a lobbyist killed by Gormogon's other apprentice among the 10,000 skeletons in the Jeffersonian's bone storage room called Limbo. However, Zack still maintained a loyalty to his friends. As pointed out by Brennan, he was willing to injure himself to keep Hodgins safe. He gives up the location of Gormogon's house after Brennan makes him realize his logic is faulty.
At the end of the episode, prosecutor Caroline Julian cuts Zack a deal. He pleaded guilty to killing the lobbyist and declared "Non compos mentis", thus committing him into a mental asylum rather than to prison.
Zack is no longer a regular character on the show, but series creator Hart Hanson 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."
The episode "The Perfect Pieces in the Purple Pond" reveals Zack is receiving psychological treatment from FBI psychologist Dr. Lance Sweets. It is also shown at least Hodgins and Angela have both been in contact with Zack during his confinement. Hodgins is shown bringing him a mathematical riddle to solve. In his session with Sweets, Zack admits to feeling guilty for killing the lobbyist but claims he was not actually crazy, arguing he committed the crime for what had appeared to be perfectly logical reasons at the time. "I was wrong, not delusional," he says. Sweets believes Zack should feel more guilty about killing the lobbyist and less about having been taken in by Gormogon's rhetoric.
Towards the end of the episode, Zack escapes from the institution. It is revealed he could have escaped at any time but did not feel it was necessary to do so until that particular moment. After helping his co-workers solve the case, he willingly returns to the institution with Sweets. While returned to the asylum, Zack tells Sweets that, while he had helped Gormogon find the lobbyist, he himself had not actually stabbed him. In other words, Zack believes he killed the lobbyist; but, from a legal standpoint, he is considered only an accessory or co-conspirator. Sweets insists Zack change his story, but Zack refuses. He fears, if his secret were to come out, he will find himself in prison, where he is sure to do very poorly. He reminds Sweets, as Zack's therapist, he must not reveal his secret because, if Sweets were to do so, he would be violating doctor-patient confidentiality. The episode closes with Zack behind bars at the institution, and Sweets keeping his secret.
In the Season 4 finale, Zack is considered a suspect when a man is murdered in a popular nightclub owned by Booth and Brennan. Zack is described by Vincent Nigel-Murray as "the type of moron who goes to jail for a murder he didn't commit", suggesting that, on some level, Booth knows Zack is innocent. At the end of the episode, it is shown that the entire thing was in fact a dream about an alternate time line that Booth had while unconscious and part of a new book Brennan was writing.
Zack also returned in the 100th episode as a flashback to Booth and Brennan's first case together, although he has yet to return to the show in "reality".
Later on, Hodgins says that Zack will be in the asylum "forever", hinting that Zack would be in the asylum on a permanent basis and would never even be released into the general public. Also, in the episode "The He in the She," Hodgins tells a new intern, Vincent, that Zack would be locked up for the rest of his life.
Despite his intelligence, Zack is unsure of himself and though he has come up with crucial insights vital to some of the team's cases, he is unable to forcefully express his opinion to Dr. Brennan. This may be due to romantic feelings toward her. When he discovered Temperance's own Forensic Anthropology professor had become her lover, Zack repeatedly wondered aloud whether he might enter into a similar relationship with Dr. Brennan. He was quickly disabused of the notion by his colleagues. His inability to pick up on pop culture references or jokes was often a source of comedy in the show. Other characters, especially Booth and Hodgins, were often annoyed or turned off by his lack of social skills. Hodgins once called him a "dull Vulcan" in exasperation.
Zack appears to have an on and off-again relationship with "Naomi, in Paleontology", despite hints in the first season she was dissatisfied with his sexual prowess. In the third season, they accompany each other to the annual Jeffersonian Institute Halloween party, agreeing to dress as a cow (Naomi in front, Zack in back) ("The Mummy in the Maze") and in "The Parts in the Sum of the Whole" he talks about her again. Zack has no problem making inappropriate comments about others' personal lives, and has asked Agent Booth for advice on sex and women, requests which Booth characteristically ignored; and at one point threatened to "take out [his] gun and shoot [Zack] between the eyes" if he continued to ask him those questions. Angela answered his question once, (on one occasion even recommending him to "reap the benefits of [her] sexual wisdom"), and Hodgins gave him a pocket-sized Kama Sutra to help him out, revealed in the season three finale ("The Pain in the Heart").
Very little is known about his childhood. In "The Wannabe in the Weeds" episode from the third season, it was discovered Zack was in singing classes during his childhood as a way for his parents to help integrate him socially. Though it did not appear to work, he demonstrates his talent when Hodgins doubted him. He has fond memories of receiving his first microscope ("The Girl with the Curl"), and when he was six, he had a pirate eyepatch, ("The Man with the Bone"). He said he used to play horses as a child and has a Michael Jackson glove. It is also known he attended a private high school ("A Boy in the Tree"). His interests include model airplanes ("The Killer in the Concrete"), watching basketball ("The Soldier on the Grave"), and science fiction: Firefly ("The Man in the Fallout Shelter"), Lord of the Rings ("The Woman at the Airport"), Star Wars, Star Trek, Stargate, Battlestar Galactica ("The Superhero in the Alley"). He does not dance, because he's been told he "looks like a marionette in a windstorm" (The Man in the Wall). Although well-meaning, helpful, and friendly, when a situation calls for social interaction or intuition, he is often lost. Further evidence of his social ineptitude can be seen in the frequent, on-screen coaching in social matters he gets from Jack and Angela. He is very literal-minded, and is often confused by colloquial expressions or metaphor, despite his high intelligence. His attempts to use such expressions meet with mixed success, such as referring to a skull he'd cleaned as being "clean enough to eat off of" ("Two Bodies in the Lab").
In the episode "The Killer in the Concrete", Booth is on the phone with Zack and Dr. Brennan while looking for "Icepick" at a model airplane enthusiasts gathering. Unaware of Zack's interest in planes, Booth comments every "airplane freak" in the area was at the event, and Zack corrects him by saying the enthusiasts prefer to be called "pilots." Zack mentions forensic anthropology is only one of his areas of study, another is applied engineering, and he is extremely adept in practical aeronautics.
As seen in the episode "The Man in the Fallout Shelter" Zack has a large family and greatly values them, remarking the true meaning of Christmas is "Brothers, sisters, nieces, nephews; 40 people who love you and are happy to see you." Also in the first season, he reveals to Dr. Brennan he uses his vacation time to visit his family. While he does not necessarily enjoy these visits, he goes because they love him ("The Man in the Wall").
Even in the asylum, Zack apparently still has some degree of contact with his old colleagues, Hodgins occasionally visiting him with puzzles for him to solve and Sweets having formed a diagnosis of Zack (although he is unable to reveal that Zack is not actually 'crazy' due to doctor/patient confidentiality); Booth's dream sequence in "The End in the Beginning" implies that Booth is aware on some level that Zack is innocent, but this has never been explored in the real world.
- "Judas on a Pole". Bones. Season 2. Episode 11. December 13, 2006. Fox.
- "Stargazer in a Puddle". Bones. Season 2. Episode 21. May 16, 2007. Fox.
- "Pain in the Heart". Bones. Season 3. Episode 15. May 19, 2008. Fox.
- Mitovitch, Matt Webb. "Exclusive: Bones Boss Responds to Finale 'Zack-lash'", TV Guide, May 21, 2008.
- Hart Hanson, Dana Coen, Sanford Bookstaver (2005-11-29). "The Girl in the Fridge". Bones (TV series). Fox.
- "The Woman in the Sand". Bones. Season 2. Episode 8. November 8, 2006. Fox.
- Hart Hanson, Patrick Norris (2005-09-27). "A Boy in the Tree". Bones (TV series). Fox.