Dr. Robert Cromwell performs a delicate operation, that has never been done before, and the patient dies. Charged with malpractice and manslaughter, his trial is national news but the jury acquits him. But the court of public opinion is still against him, and the medical board is meeting to decide whether or not to take his medical license away from him. Before they do, Cromwell, an amateur pilot, decides to join his friend, WWI Ace Donald Evans, on a flight to Alaska looking for a shorter route to Japan by following the Aleutian Islands. They crash in Alaska and Evans is killed, but Cromwell is rescued by a fur trapper named Tom Ross. He takes Cromwell to Armstrong's Trading Post, where is is nursed back to health by Klondike, a girl who works for Armstrong, and was engaged to marry Armstrong's son Jim. The latter is suffering from the same disease that Cromwell's last patient had. Mark talks Cromwell into performing the same operation again and, this time, it is a success.