Harm's friendship with Capt. Volkonov puts him in a precarious position when a Russian submarine blows up and the Russians claim that a U.S. submarine was responsible. It's up to Harm to convince his friend (& the world) that the accident was caused by a faulty new Russian torpedo, without divulging highly classified material.
Meanwhile, Mac is sent onboard the USS Watertown to observe when the Congressional committee headed by Rep. Latham investigates as to why women are not allowed to serve aboard submarines.
Renee & Mic are left behind wondering whether their really is something between Harm & Mac.