Older Hank Armitage and younger Sam Wells lead a combined lonely existence in their relative seclusion as a lighthouse keeper and his assistant, respectively, their lighthouse built on what would otherwise be a small pile of rocks off the coast. One or the other will make the necessary trip via boat into town once a week for supplies as someone needs to be at the lighthouse at all times. Sam has been stringing along a local girl, Connie, on the eventual promise of marriage when the time is right. Connie has her own troubles without Sam, as she has attracted some unwanted attention which led to her being fired from her job at the cannery, unemployment which makes her want marriage to Sam be sooner than later in her loneliness. When Connie, upon meeting Hank, learns that Sam may not be the forthright guy she knew and loved, with Hank having no reason to lie in only telling what he believed to be benign truths and not knowing about Sam and Connie being in a relationship, Connie, solely in an act of spite, decides instead to marry Hank who has fallen in love with her, she to move out to the lighthouse. Those confined quarters with newlyweds Hank and Connie, and spurned Sam who believes Connie still truly loves him and will never love Hank, lead to an environment of tension, the only one not knowing what is going on being Hank. What happens in this triangle is affected by what each wants with respect to the other two, and as time goes on what each thinks the other two want.