The Masks of Death

Sherlock Holmes (Peter Cushing) has retired. But when MacDonald (Gordon Jackson) asks him to take on another case, he says yes. There have been some mysterious murders, and there are no visible causes for the deaths. At the same time Holmes gets this case, Graf Udo Von Felseck (Anton Diffring) gives him another case: find a young and missing prince to prevent war between Germany and England. But Von Felseck is not as honest as he seems...