一个女孩突然从北海道的度假区凭空消失了。她的母亲为寻找女儿的踪迹，舍下丈夫踏上寻女的旅程。母亲的心中隐藏着无法对丈夫或警方明言的秘密。原来女儿失踪事发当时她正与外遇的对象翻云覆雨。为了弥补她的愧疚，靠着仅有的一些不确定的线索，她与一位癌症末期的刑警一起踏上了寻女的旅途。剧情发展出人意料，铺陈也十分细腻，剧情悬疑高张。

Kasumi is in the midst of an affair with Ishiyama, one of her husband's clients. When Kasumi and her family visit Ishiyama's villa in Hokkaido, she plans to abandon them to be with Ishiyama. The next morning, her daughter Yuka disappears, which throws Kasumi's life into turmoil. Years later, Yuka remains missing, and Kasumi journeys back to Hokkaido with Utsumi, a terminally-ill former detective, and tries to follow any leads she can.