Ducky announced his intention to retire from NCIS in the previous episode, and “Silent Service” revealed how the longtime Chief Medical Officer was leaving the crime-fighting game.
The bad news is that he really did retire from his post; the good news is that he’s not gone for good.
NCIS has teased the possibility of a member of the team leaving a couple of times this season, and it became pretty clear that the show was going to follow through with one of them leaving.