ÂWhen Navy Lt. Lauren Ross is found dead from a broken neck in the custodial closet of the Pentagon, our team is called into investigate. Surveillance video indicates that she was strangled by her co-worker Lt. Eric Donner who was once part of the Special Warfare unit but was now working a clerical job at the Pentagon following an injury. However, when Donner shows up dead and Ducky reveals that he died of a heart attack well before Rossâ€™ murder, our team is at a loss. Ducky eventually discovers a substance in Donnerâ€™s ear that is linked to realistic silicone masks often used by the CIA when engaged in covert operations. Rossâ€™ killer turns out to be Donnerâ€™s commanding officer, Nelson Tunney, when he served in the Special Warfare unit. Donner was going to switch out a file, which incriminated Tunney of murder while on a mission, but died before he could do so. Tunney made a mask of Donner in order to get clearance at the Pentagon and Ross ran into him and realized that it wasnâ€™t Donner. Our team tries to find the identity of the eye-ball that was left in Tonyâ€™s drink in #182. We suspect that itâ€™s linked to our port-to-port killer who is still on the run.