A doctor is sentenced to ten years for treating an escaped felon, tries to escape, and exposes a corrupt prison warden.
In France Gustave LeBrun (Stuart Holmes) is sentenced to Devil’s Island for treason. On a train a man in a uniform helps him escape; but as they get in a car, LeBrun is shot. His gang takes him to Dr. Charles Gaudet (Boris Karloff), who immediately treats his critical wound. Before the police arrive, the rest of his gang departs. Gaudet is arrested and is tried for aiding and abetting a convicted traitor. Gaudet protests he only did his duty as a doctor, but he is sentenced to ten years and sent to Devil’s Island.
Col. Lucien (James Stephenson) assigns Gaudet to timber cutting. Gaudet tells Dr. Duval (Edward Keane) to hospitalize André or he will die. Gaudet learns he has no hope for an appeal. André drops a shovel, causing a carriage with Madame Lucien (Nedda Harrigan) to speed up, and her daughter Colette is thrown out. A guard is assaulted, but the men are caught. Dr. Duval tells Col. Lucien and his wife that only Gaudet can save their daughter with a brain operation. Gaudet insists the men’s lives must be spared. Gaudet steals some ether and operates. Madame Lucien thanks him, but Col. Lucien has him put in the hole. The guard was killed, and Pierre is executed by guillotine. Demonpre tells Madame Lucien she can help Gaudet by giving him money. Demonpre bribes a guard and gives Gaudet cash. Gaudet uses ether on a guard and escapes with five men in coffins. Col. Lucien is alerted, but trustee Hawkins steals papers from Lucien’s safe. Six guards get on Hawkins’ wagon, but he escapes and warns Gaudet. The seven trudge through the swamp and take a boat. Madame admits to her husband that she helped Gaudet. On the boat they run out of gas but have water.
A ship sees them and brings them aboard unconscious. Later Gaudet says they are fishermen, but they see they are convicts and take them to Devil’s Island. Col. Lucien gets his bank book back. Madame Lucien overhears and goes to the mainland to find to Gov. Beaufort (Charles Richman), who is with the Minister of Colonies. They hurry to stop the execution of Gaudet, who accuses Col. Lucien of murdering him to cover up his crime. The Minister of Colonies arrives and orders Gaudet released. Gov. Beaufort arrests Col. Lucien and says he will be investigated. The Minister of Colonies tells Gaudet that he is pardoned. In the final scene Gaudet says good-bye to Madame Lucien and Colette.
By contrasting the healing skill of a doctor unjustly convicted to the cruelty of a prison colony with a corrupt warden, this drama makes a strong case for major reforms.