A shifty financier, who invested money in a cabaret, is found in his theatre box shot dead during the grand premiere of a new spectacular revue. The shot came from the stage --- and with the help of the stage manager, the detective Dr. Helder is on the heels of the murderer. The primary suspect is the lead actress, Carmen, who was in constant conflict with the victim. But then there's her stage partner and ex-lover Fred, as well as the bitter Lydia, who's been dropped from the ensemble thanks to Carmen.