Undertow

S7 E24: The team searches for a man who goes missing after a late-night dive and try to zero in on who may be responsible for his disappearance. Meanwhile, Danny and Elena take their relationship to another level. Academy Award winner and recurring guest star Martin Landau appears as Frank Malone, Jack's father, and recurring guest star Adam Kaufman appears as Brian Donovan, the father of Samantha's son, Finn.