On the island of Wayo Wayo, every second son must leave on the day he turns fifteen as a sacrifice to the Sea God. Atile'i is one such boy, but as the strongest swimmer and best sailor, he is determined to defy destiny and become the first to survive.

Alice Shih, who has lost her husband and son in a climbing accident, is quietly preparing to commit suicide in her house by the sea. But her plan is interrupted when a vast trash vortex comes crashing onto the shore of Taiwan, bringing Atile'i with it.

In the aftermath of the catastrophe, Atile'i and Alice retrace her late husband's footsteps into the mountains, hoping to solve the mystery of her son's disappearance. On their journey, memories will be challenged, an unusual bond formed, and a dark secret uncovered that will force Alice to question everything she thought she knew.