Sean Harmon son of Mark Harmon (Leroy Jethro Gibbs) star of N.C.I.S guest stars in this episode. He also plays the young Leroy Jethro Gibbs on N.C.I.S "flashbacks" episodes.
The alias which Hanna uses is "Agent Gallo", the name of Robert Patrick's character in Scorpion (2014).
Hetty has also appeared in Scorpion.