Jeffrey De Serrano

While investigating a serial bomber's attack on a small town, Gideon learns that the perpetrator is a protégé of his nemesis, who had murdered his previous team of profilers.

Callen takes on a secret project, leaving the team in the dark; when Hetty shuts down Callen's operation, the team must locate him before he gets in trouble.

The mole has once again compromised the NCIS team as planted evidence results in the arrests of Callen, Sam, Granger and Deeks, on the day Under Secretary Duggan returns for Hetty's resignation.

Sam fears for his family's safety when his wife is called to resume a former CIA cover after a case suggests ties to the infamous Sidorov and his stolen nuke.

Victoria contacts her exes to learn where things went wrong while she is stuck in the hospital; Joe and Melanie have fantasies about a coma patient; Elka and Mamie bring Las Vegas to Cleveland.

Walt and the team look into the disappearances of several Cheyenne foster children and an unregistered sex offender.