A young surgeon teams up with an ambulance driver to fight hospital corruption.
City hospital head Dr. Averill (Reginald Mason) assigns his future son-in-law Joe Bradley (William Boyd) to be a surgeon with an ambulance. Steve Brennan (William Gargan) drives Joe fast with the siren going. Joe and Steve both fight a crazed man with a knife and end up as patients. Kid Miller (George E. Stone) walks in front of a car to claim money. Joe treats him. Steve suspects that Miller is faking injury. Nurse Mabel Weenie (Wynne Gibson) is hoping to marry a millionaire. Joe tells Alice Averill (Betty Furness) that he has been busy operating on patients. Steve carries Miller out and hits him. Dr. Averill fires him and Mabel too; but he is persuaded to give them their jobs back. Joe agrees with Steve that Miller was probably not hurt. Steve thanks Joe and tells him that Miller is a gangster. Miller goes to Tom Rourke (Edwin Maxwell), who hits him for making a pass at Steve's girl.
Gangsters are killed, and Rourke's gang takes control of the hospital because of his political power. Rourke tells Dr. Averill what to order for the hospital. Joe throws out a lawyer who tried to get a patient to sign a paper. Steve tells Joe that Rourke gets information from Averill's office. Joe complains to Averill about Rourke getting records; but Averill takes a phone call from Rourke. Joe apologizes to Steve and begins packing; but when Steve says he wouldn't stay and fight either, Joe decides to stay.
Mabel learns that her millionaire patient is broke, and she goes out with Steve. Steve gives Mabel a ring and kisses her. Rourke sells 1,000 cans of condemned ether to the hospital, and Averill signs for them. The lawyer complains to Rourke about Joe. Joe and Steve are sent to an ambush. One man throws a knife into Steve's back, and Joe fights two others until the police arrive. Joe operates on Steve, telling Mabel that Steve was hurt because of Rourke. Steve stops breathing and dies. Mabel cries and blames Rourke. Joe sees the cans of ether and accuses Averill of murder, saying he will expose the hospital. Rourke gives Joe a concussion with a gun. Rourke tells Averill to get rid of the ether after Joe is operated on. Averill sends a message by intercom, and the nurse has the ether stopped. Rourke asks Mabel to help him escape, and she shoots him; but she is exonerated. In the final scene an ambulance service is dedicated to the memory of Steve Brennan.
This melodrama explores how "ambulance chasers" and corruption can effect the working of an urban hospital.