Zack White

Zack White is the secondary antagonist of the 2014 mystery-thriller film Non-Stop. He was secretly the accomplice of the film's antagonist, Tom Bowen.

History
Federal air marshall William Marks befriended White while boarding the plane. When Bowen sends numerous blackmailing text messages to Marks for a passenger killed every 20 minutes, Marks hired White to trace the killer's call and it was in the pocket of one of the passengers. The passenger states he's never seen the phone before, and is later killed the same way the captain was after the third 20 minute mark came around. Marks later finds a hole in the wall, deducting it to be the killer's former position as it is where he sniped the captain and passenger with a pair of fatal darts. The killer then sends a message to the TSA that Marks is a homicidal terrorist about to detonate the plane with a bomb. Seeing how there is no way to get rid of the newly discovered bomb, Marks throws the explosive in the back of the plane and smothers it with items to weaken the blast, convincing the passengers to work with him.

Marks re-watches the blackmail video of him insulting the passengers and notices how a certain man, Tom Bowen, is slipping a phone into the deceased passenger's pocket from before. Realizing that Bowen is the culprit, Marks find and engages him in a fight, and during the struggle, White revealed himself as Bowen's accomplice. It was revealed that Bowen and White were soldiers appalled by the lack of security at U.S. airports before 9/11, hoping that framing Marks as a terrorist will lead to drastically increased security. Bowen is prepared to die with the plane and shoots White, who expected to get off the plane with the money. Following another fight, Marks shoots Bowen in the head. White recovers and attacks Marks with a knife, but White dies in the explosion as Marks retreats to the front of the plane. The plane ultimately lands rough with no casualties other than White and Marks continues his normal life.