While assisting NCIS with an undercover operation, informant Elizabeth Williams is arrested and the team is unable to provide her with an alibi. Also, Callen meets with ATF Agent Anna Kolcheck who remains on suspension following her last joint case with NCIS.

The NCIS team partners with the State Department after the murder of an arms dealer is connected to a series of crimes seemingly executed by someone with elite special forces training. Also, Callen visits ATF Agent Anna Kolchec in prison as she awaits her sentencing.