A young, innocent heir Alfred Wolski is jailed for an alleged embezzlement that also disinherits him, prompting detective Denn to doubt the charges and pursue his rehabilitation.
The architect Georg Wall is sitting in his spacious Stockholm apartment. He has been waiting several hours since lunch for his significantly younger wife, Lola Wall, to appear.
Guests at a luxury hotel are horrified when they witness a man literally "disappear into thin air." The vanished man's relatives hire a detective, who goes to the hotel to investigate the disappearance.
Stephan Gregorovitch, the unwilling king of a bankrupt Ruritanian country, along with his hucksterish chancellor and musically-inclined bodyguard, travel incognito to London for some fun.