Dock cleaner Grace finds a bottle linked to Tristan, a 16th-century captain stranded at sea. She sends supplies to save his people; he worships her as a goddess and sends treasures that make her rich. As she sends weapons, medicine, even a modern ship, love blossoms across time—until the bottle shatters. Unbeknownst to Grace, Tristan trades his freedom for immortality, bound to the sea as he waits 500 years to see her again.