When Sherlock Holmes receives an unexpected caller - in the personage of none other than the great theatrical illusionist, Marco Chudinelli - he believes that it will prove a simple enough task to find the gentleman's missing twin brother. However, it soon transpires that all is not quite as straightforward as it, initially, appears - and Holmes soon learns that the man who is 'anxious' to locate his elusive sibling is, probably, involved in the man's disappearance. Confronted with the thorny problem of having to serve his client's interests whilst, at the same time, attempting to liberate his persecuted brother from the devious scheme to bring about his downfall, the detective turns to his old friend, Inspector Lestrade of Scotland Yard, for his valuable assistance. With Doctor Watson in Switzerland, on his honeymoon, Holmes is left to unravel a mystery which, even in his own experience of the baffling and bizarre, soon proves a most singular case indeed...........