Harry Beaumont, a director-composer most closely associated with MGM's musical product, does a nice job handling the tongue-in-cheek melodramatics of Murder in the Private Car. Charlie Ruggles goes through his standard drunken-detective act as amateur gumshoe Scott, who stumbles onto a dead body when he wanders into the wrong train car. Despite the fact that the private car can only be locked from the inside, several more murders occur within its walls. This means plenty of trouble for heroine Ruth (Mary Carlisle), who'd rented the car for a cross-country journey of vital importance. Before this particular odyssey is over and the murderer is revealed, the private car, with Ruth trapped inside, is separated from the rest of the train and sent hurtling backward down the tracks, loaded with dynamite! Perhaps Harry Beaumont missed his calling: judging by Murder in the Private Car, he should have specialized in serials.