Her father Max Keenan re-entered Brennan's life when she and her brother were being threatened by an old acquaintance, who turned out to be Booth's boss, Deputy Director Kirby. Max evades capture after killing Kirby, and takes Russ into hiding to protect him. Later, Max allows Booth to arrest him in order to improve his relationship with his daughter. At trial, Max is acquitted of murdering Director Kirby (due in large part to a defense Booth indirectly came up with, positing an alternate theory of the crime in which Temperance was the killer instead, creating reasonable doubt), and he begins to rebuild his life.