When Bones and Angela discuss heavy metal, Bones reminds Angela of the Norwegian band Skalla and their case, which was in Mayhem on a Cross (2009).
David Boreanaz and guest star Jack Plotnick had worked together previously in season 3 of Buffy the Vampire Slayer.
Hal Holbrook (Red Hudmore) and June Squibb (Barbara Baaker) have also appeared together in a Grey's Anatomy episode, Till' I Hear it From You 13:17.