Dowoo runs an old motel – adjacent to a lake with thousands of Korean War victims at its bottom – as well as caring for his mother who has dementia. One wintry day she disappears without a trace. In her stead, a cute little dog appears. Everyone helps kind-hearted, somewhat shy Dowoo search for her. However, when his mother isn’t found, rumours arise that he may have killed her. Has he started having doubts himself? It doesn’t help that he swallowed her tranquillisers on the day she went missing, and can’t remember a thing.