Based on a play by Owen Davis, Lighthouse By the Sea top-bills Warner Bros.' most successful male star of 1924: dauntless doggy Rin-Tin-Tin. The "human" plot involves the efforts by the daughter (Louise Fazenda) of an aged lighthouse keeper (Charles Hill Mailes) to hide the fact that her father has gone blind. A scurrilous gang of rum runners take over the lighthouse and hold father and daughter captive. Rin-Tin-Tin comes to the rescue in spectacular fashion. Legend has it that screenwriter Darryl F. Zanuck so despised the notion of writing a Rin-Tin-Tin vehicle that he came up with a scene in which the canine star carried a baby back into a burning building (that scene doesn't show up here, or in any other "Rinty" picture).