|This article does not cite any references or sources. (December 2009)|
||This article consists almost entirely of a plot summary and it should be expanded to provide more balanced coverage that includes real-world context. (December 2011)|
|Babylon 5 character|
|First appearance||Spider in the Web|
|Last appearance||Sleeping in Light (chronological), Babylon 5: A Call to Arms (airdate)|
|Portrayed by||Jeff Conaway|
|Affiliated with||Babylon 5 Security|
Zack Allan is a character in the fictional universe of the science-fiction television series Babylon 5, played by Jeff Conaway. He regularly appeared in the show from season 2 onwards. During the second and third seasons of the series he was a security officer on the Babylon 5 station. In the fourth season, he was promoted to become Babylon 5's Security Chief and he retains that position through to the end of the series' fifth and final season.
 Character description
Zack Allan's background is never explained in detail on the series. He met and worked with Babylon 5 Security Chief Michael Garibaldi in the decade between the Earth-Minbari War and the opening of the Babylon 5 space station. At one point in the series Allan thanks Garibaldi for "taking a chance" on him despite his previous personal problems.
As it turns out, his personal problems had consisted of apparent drug and alcohol abuse, which had led him to be fired from several previous jobs. However, by the time Zack is hired to work for Babylon 5 Security he had overcome his addictions and he proves to be an excellent security officer. (Garibaldi himself had been granted a similar break, despite an addiction problem of his own, by his commander and friend Jeffrey Sinclair).
Over the course of the series Zack is revealed to be honest, trustworthy, reliable, a tough and skilled fighter in hand-to-hand combat, a trained Starfury pilot, and rather unlucky in romantic situations (striking out rather quickly, if inadvertently, with Lyta Alexander in the made for TV movie Thirdspace). He is also depicted as being not particularly intellectual, "book-smart" or quick-witted, but rather "streetwise" and shrewd in sizing up other humans or aliens. He is also apparently at least nominally religious, stating a belief in heaven.
He also has an optimistic and easygoing personality that others usually find appealing, and he does not appear to stay depressed or downbeat for very long. He is quite modest, and this often works to his advantage when compared to the other, often more egotistical and aggressive, characters on the series. Zack's voice also gets raspier as the series progresses. In the episodes Voices of Authority and Atonement, Zack reveals his ongoing irritation with finding uniforms that fit properly.
Briefly in season 2 and 3, Allan was a member of Nightwatch, a civilian para-police force created by Earth Alliance President Morgan Clark to expose and arrest "traitors to Earth". True to form, Zack joined Nightwatch for the bonus pay they offered, without paying much attention to their political views and fascist nature. However, he had the truth of their nature driven home when a shopkeeper accused of sedition for publicly criticizing Clark's presidency was physically dragged away from his store and imprisoned by Nightwatch officers in the episode, "The Fall of Night". After this experience Zack agreed to help Babylon 5's command staff, eventually playing a critical role in "Point of No Return" in leading the bulk of the station's Nightwatch into a trap set up to capture them.
 Chief of Security
Allan was the second aide to B5 Chief of Security Michael Garibaldi from 2259-2261. Following Garibaldi's resignation as chief of security in season 4, Allan was appointed Chief of Security. He held the position for many years; except for a brief stint back on Earth, he remained there until the station was decommissioned in 2281. Because of this, he was the only one not to receive his invitation to Sheridan's farewell party in Sleeping in Light, though Allan would still meet Sheridan one more time as Sheridan took one last walk through the station.
In Sleeping in Light, he walked with a noticeable limp, which has never been explained on screen. In the voiceover commentary of the episode, series creator J. Michael Straczynski explained that Zack was involved in heroic activity and lost his leg. In keeping with his previous experience with uniforms, it is suggested that the prosthetic he was supplied with never fit correctly. Later in the episode, after the aged and abandoned Babylon 5 was destroyed and the Drakh influence on Centauri Prime was exposed and eliminated, Zack joined the Rangers and became Centauri Emperor Vir Cotto's assistant and (presumably) a direct liaison between the Emperor and the Interstellar Alliance.