NCIS comes under attack by a mysterious enemy from the past. Also, Vance tries to mend fences with his estranged son by explaining why, despite the ongoing dangers of his job, he still chooses to stay at NCIS
McGee: Curtis? You OK? Curtis: I will be after three more minutes of Vitamin D. McGee: Got the basement blues? Curtis: Working in a room with no widows puts you in a dark place.