McGarrett turns to Kamekona as a silent partner for the restaurant. He brings $250,000 in two suitcases. A Russian sub surfaces off Waikiki Beach. McGarrett takes an inflatable raft out to the sub. He gets taken inside. Grover said the Russian government doesn't know why the sub is there. The captain has been shot during a mutiny. Yuri Petrov, the man who shot the captain, escaped through the torpedo bay. McGarrett threatens to have the consular agent sent home if he doesn't cooperate. He tells McGarrett not to board the sub again, or it will be considered a hostile act. Petrov shoots a cop and steals a cruiser. McGarrett goes back to the sub for another lead. He appeals to Vasili Shirikov, the acting commander, to figure out what Petrov wants. Petrov looked up Lee and Nancy Sterling with the squad car's computer. Grover, Tani and Junior find the Sterlings tied up in chairs and drowned in the pool. Both were tortured and electrocuted. One of Petrov's classmates thinks he's on a revenge mission on deep-cover agents who killed his parents. Junior finds a go bag in the Sterlings' attic. Tani discovers a hidden room behind a bookcase. The Sterlings called Monica Shore, another sleeper agent, who is hiding out at the Russian embassy. The guard at the embassy gate has been shot. Grover finds Yuri holding Monica at gunpoint and flushes him out. Yuri and McGarrett brawl until McGarrett comes out on top. McGarrett arrests Monica. The sub leaves. The rest of the sleeper cell gets swept up as well. McGarrett and Danny return to see Kamekona hard at work on their restaurant. He also picked up a liquor license. He's already renamed it Kamekona's Italian Bistro. Tani shows Junior the gun she found at Adam's, which is the weapon that killed Noriko.