The Moroville Covenant

Clash of Shadows is the 18th episode of Season 12 in the original version of Hawaii Five-O

Synopsis
Israel's celebrated Nazi-hunter Yuri Bloch has apparently been killed in Honolulu while trying to gather information about a war criminal named Emil Klaus. Knowing the Bloch would only have come to Hawaii if a former Nazi were hiding there, McGarrett and Five-O conduct their own search for Klaus -- while Bloch's partner lies badly wounded in a safe house, and the woman caring for him does what she can to assist while undercover.