Silent Night
performed by Dinah Washington

The fingerprints of a presumed dead petty officer, Ned Quinn, turn up at the scene of a double homicide. Claiming innocence, Quinn explains he was in the garage working for the victims when they were murdered. While fighting with metro police who want Quinn prosecuted immediately, the team discovers evidence linking a security guard to an emptied safe at the crime scene. Having been exposed, the guard shoots McGee with a taser and unsuccessfully tries to escape. Quinn, explaining that he went "undercover" after his apartment burnt down believing his wife and daughter would be better off with the service benefits from his presumed death, is convinced by Gibbs to rejoin his family for Christmas.

Phil has a severe case of appendicitis, which the group learns will kill him if they cannot remove his appendix. They choose Gail to perform the operation, and she reluctantly agrees as long as she can practice on something. Finding no viable bodies in a local morgue, Tandy and Todd decide their only choice is to dig up the recently deceased Gordon. As they drag Gordon's body to Gail, they see she has found a medical dummy to practice on, so they quickly re-bury the body. In space, Mike Miller succeeds in reentering the space station since his suit is still tethered to it. Later, he tells his newborn worm friend "Phil", that he has decided he must attempt to return to Earth. Gail and Todd begin operating on Phil, but soon encounter complications, especially with Melissa confirming her suspicions that the two have been seeing each other. As Mike's landing capsule begins tumbling upon reentry into Earth's atmosphere, Phil flatlines.