Synopsis

Keel pulls a young woman from the Thames, reviving her. He is taken to the Radeck State Circus, where the trapeze artist is kept under guard, her face concealed by bandages following an accident. The performer, known as the 'trapeze girl,' is revealed to be the daughter of a scientist who has defected, and she is intended as leverage to compel his return. Upon learning this, Keel and Carol are captured by Zibbo the Clown, who threatens Carol's life should the police investigation not be halted.