A psychiatrist begins treating a woman who appears to have lost her memory and refuses to speak, revealing emotion only when she hums a particular song. Following that clue uncovers the story of a pregnancy, an absent lover who left for work at sea, and a period when despair brought the woman close to ending her life. The mystery gradually reconstructs how love, abandonment, chance, and memory brought her to the clinic and whether understanding the past can change what comes next.