作为家庭中年纪最小的成员，萨姆因为害怕家人离开后的孤独，而在度假小岛上开始了自己秘密的“孤独训练”。而岛上古灵精怪的女孩苔丝则绞尽脑汁想要和素未谋面的生父见面。萨姆没想到这暑假的怦然心动不仅会打乱他培养自己适应孤独的训练安排，还会将他带入另一场冒险旅程中。在这个悠长的夏日假期里，两人相依为伴，收获了最美好的记忆，萨姆也意识到人生并非一座孤岛，相伴本身就是意义。

A close-knit family is disrupted when the father fails to resurface during a professional dive. No funeral, no goodbye, just a house full of memories. Burdened by the elusive loss, Merel evades her husband's death and everything related to it. Her young children become entangled in their search for answers, eventually bringing the family to a hard stand. Merel has no choice but to face the loss in her own unique way, to start a new life together.