Four months after the events of the Navy Yard Bombing, the body of NCIS's facilities manager is discovered in her car. Due to the fact that she disappeared without a trace on the day that the Navy Yard was attacked, the NCIS team begin to wonder if she played any role in the bombing but things change when acting Medical Examiner Jimmy Palmer discovers that the victim was shot which has the team realizing that the supposed accident is actually murder, prompting them to launch an investigation as they search for the killer while in the aftermath of the bombing, the team undergo psychological evaluations to determine if the attack has affected them.