The NCIS team is due for a psychiatric evaluation. Director Vance agrees, with much hesitance to let Dr. Rachel Cranston follow and evaluate the NCIS team during a murder investigation. Commander Vincent Reynolds was found dead and shot in the chest on a Navy boat.
The team is unable to find a weapon. They do find tape residue on the victim's finger and this indicates that he may have pulled the trigger himself. The victim, a single, childless man was only just over a year away from retirement. After deeper digging, NCIS learns that he had been involved in a long term affair with his best friend's wife.
Reynolds did indeed commit suicide. He could not face the fact that his career was nearly over and he had no family or loved ones to go home to once it was all done. Reynolds' direct reports had so much respect for their Commander that they wanted to protect his honor by making his death look like a murder instead of a suicide and they got rid of the evidence by disposing the gun.
Dr. Cranston learns a great amount during her evaluation of the team. She finds that they all have a large number of personal issues. It turns out that Dr. Cranston is the sister of Kate Todd, a former NCIS agent who had been killed and Gibbs had authorized her presence there.