The series presents the adventures of a time traveler. At the heart of his plot is the story of Claire (Beauchamp) Randall, a young woman who worked as a nurse during World War II. She is married to Frank Randall, a historian, possibly a spy during the same war. The action begins in 1945, after the reunion of the two at the end of the great world conflagration. Claire had married Frank out of love, and now they were in Inverness, Scotland, trying to resume their marriage for a second honeymoon. and the Rev. Wakefield, passionate about the Jacobite period, assists him in his research into the family tree. From him he learns about his ancestor Jonathan Wolverton Randall, nicknamed Black Jack Randall, a dragon captain who fell in battle at Culloden (1746).