sentences:  We find out that Booth has a 4-year-old son named Parker (because his mother didn’t marry him, his parental rights are vague), and that Billy Gibbons from ZZ Top is Angela's father.With everyone else in the lab celebrating Christmas with secret Santa gifts, Bones decides to track down Ivy and reveal the lethal mystery behind Lionel's disappearance to her.Bones does this on Angela's advice.