Dr. Karl Bernhard boards the ocean liner Germania , headed from Bremen to New York, in order to seek a reconciliation with his wife Sybil, who left him without explanation. The ship's physician, Dr. Veith, gives his post over to Karl temporarily, as it is too late for Karl to buy passage. Nurse Morgan guides Karl on his rounds, during which he treats old Mrs. Webber, who sacrificed a much-needed operation so that she could afford third class passage to see her son in New York. Steerage passengers include Edward Thorndyke, a former manufacturer who was jailed for embezzlement, and dizzy blonde Milli Lensch, who is desperate to get up to first class. When the ship stops at Cherbourg, France, Sybil boards with her lover, wealthy shipping magnate Alex Stevanson. A short time later, Karl saves the life of a woman who fell overboard, inspiring the admiration of the cold Nurse Morgan. He then rushes to Sybil's cabin, but she refuses to allow him in. Sybil hysterically seeks Alex's assistance in ridding herself of Karl, but Alex is indifferent to her troubles, because he has just met beautiful opera singer Luise Marheim. After successfully delivering a baby, Karl confronts Sybil and knocks out Alex. Uninterested in her domestic problems, Alex leaves Sybil. In the meantime, Milli leaks a stock tip to the steerage passengers that she learned from her new boyfriend, who heard it from Alex. The steerage passengers then press Thorndyke to invest their last pennies for them. After Sybil surreptitiously steals Karl's gun, she vows to destroy Karl and Nurse Morgan's lives, because she is jealous that they have fallen in love. Later, Sybil shoots Alex while he writes her a check, and Karl takes the blame. Alex's murder causes the stock to plummet, but Thorndyke never invested the money, so the steerage passengers' meager fortunes are saved. Nurse Morgan then confesses to Karl that she is "doomed for all eternity" because in a suicide attempt years earlier, her children died but she survived. Sybil commits suicide after leaving a confession note clearing Karl. This leaves Karl and Nurse Morgan to begin a new life together, as the ship docks in New York.