Mystery Liner is a 1934 American Pre-Code film directed by William Nigh, starring Noah Beery, Sr., and based on an Edgar Wallace story originally published in the Saturday Evening Post in 1924. The film was entered as a feature attraction at the 1934 International Exhibition of Cinematographic Art in Venice, Italy, the forerunner of the Venice Film Festival.
Captain Holling (Beery) is relieved of command of his ship after he suffers a nervous breakdown. His replacement, Captain Downey (Howard), takes over the liner just as it is about to be used for an experiment in remote control.
Professor Grimson (Lewis) has devised a system for controlling the ship from a land-based laboratory. However, as Grimson demonstrates the system, a rival group is listening in, hoping to use the device for its own purposes.