In one of the most bizarre episodes of the war, Hitler's deputy and confidant, Rudolf Hess, the man who had written Mein Kampf as Hitler dictated it, flew across the North Sea and parachuted into Scotland on May 10, 1941, to negotiate a peace agreement. Hitler had known nothing about Hess's intention and was furious for months after he found out about it. The British, meanwhile, didn't know what to make of Hess, but concluded he was mentally unbalanced. This was also the line put out by the Nazis who said Hess had suffered a hallucination.
Sources: British National Archives