While clearly, there was a lot of things going on with the Bones finale. Apart from the Bones-Booth romp, Stewie, and Motley Crue, however, there was also the much-anticipated return of Zack, played by Eric Millegan, who was replaced in season 4 after he received his doctorate in forensic anthropology in the sophomore season. As for Emily Deschanel, who plays the titular character on the Fox procedural, having Zack back on the Bones set was "wonderful."
"I enjoy his company so much. I became friends with him over the years, like I have with most of the cast, and it was really hard to not have him around all the time. But that said, when he came back for the finale, it was as if no time had passed. He just walked in, and it was great to act with him again and hang out with him on set. It was a breath of fresh air."