The Voice on the Wire (1917)

Episode 1: "The Oriental Death Punch" Alvin Van Cleft has a penchant for chorus girls, particularly Polly Marion. One night they leave a café and enter a taxi, closely watched by two muffled figures. As Van Cleft and the girl are riding through the park Van Cleft falls into a stupor, a mysterious hand which seems to have no attachment to a body, enters the cab and kills Van Cleft. Later Howard, his son, is notified by a mysterious voice that his father has been murdered and is the third victim, two others interested in chorus girls having preceded him. Howard notifies John Shirley, interested in criminology, and Professor Montague, a prominent physician, and they, together with Cronin, head of a detective agency, start working on the case. Shirley arrives at the conclusion that Van Cleft was murdered by the Japanese death punch, Sen Si Yao, as he is telling this to his friends he receives a telephone message that Cronin is in Bellevue Hospital with a crushed skull and that Montague may be the fourth victim. Shirley visits Cronin, who tells how he was beaten by two chaps who had been in the same taxi with him. Shirley then receives a message that he will be the next victim if he does not stop meddling in others' affairs. The professor, to the surprise of Howard, disguises himself and goes out the back way; as he jumps over the wall he is attacked by two thugs, whom he overpowers and marches to the police station.