Brennan's father Max Keenan is on trial for the alleged murder of FBI Deputy Director Kirby. Everyone on the team, except for Brennan, is called as a witness for the prosecution during the trial. Brennan on the other hand is the forensics advisor for the defense, and she must rely on both her dedication to her family and her skill as an anthropologist to help free her father.
The rest of the gang fall for Sheldon's twin sister, and Leonard's plan to win her heart is derailed when Sheldon declares he'll be the one to decide who can date her.