Zack is Back in Season 5, Episode 16: "The Parts of the Sum of the Whole" Tweet November 29, 2010 by Jenny McGrath Related: Bones, Zack Addy , Season 5 Episode 16 Credit: The 100th episode of Bones flashes back to Booth and Brennan's first case. That means we get to see Zack again! We missed you, buddy.
