David Tolliver is a railroad signalman, happy with his job and beautiful wife Sally. Generous to a fault, he offers room and board to a mysterious co-worker, Joe Standish. David is unaware that his new tenant is a former convict until he tries to rape his wife. Throwing the madman out of his house, David tries to resume a life of normalcy with Sally. Standish hides nearby, biding his time until he can attack the shaken young woman again. While trying to prevent two passenger trains from colliding, David learns that his wife is still in danger. If the signalman leaves his post, he could be responsible for the biggest train wreck in history. But if he stays, it may cost Sally her life.
Billed as a 'Universal Super Jewel Production', The Signal Tower is one of the earliest masterpieces from director Clarence Brown. In the coming years, he would make Greta Garbo a star in America with Flesh and the Devil (1926) and A Woman of Affairs (1928). After showing Hollywood Garbo could talk in Anna Christie (1930), Brown would craft some of the best films of the 1930s and 40s, including A Free Soul (1931), Anna Karenina (1935), The Human Comedy (1943), National Velvet (1944) and The Yearling (1946). Legendary actor Wallace Beery would transition from his villainous part in The Signal Tower to playing the heroic Professor Challenger in The Lost World (1925) the following year. His fame would only grow in the sound era with unforgettable roles in Min and Bill (1930), The Champ (1931), and Treasure Island (1934). At one time, Beery was the highest paid actor in the world. The Signal Tower was the third screen credit for a then-seven-year-old Frankie Darro (he had made his film debut in The Judgement of the Storm earlier that year.) The son of circus aerialists, Darro appeared in numerous silent films as a youngster (including a series of westerns opposite Tom Tyler) and found great success as the lead in William Wellman's Wild Boys of the Road (1933). Eternally youthful, he played teenage roles well into his twenties.