Following the death of his wife professor Kyoichi leads a solitary life by the sea. A stray cat called Mii, who was being fed by his wife, not only continues to drop by, but also seems to be visiting the altar Kyoichi has set up for his deceased wife. While uncomfortable with the cat and its visits, he nonetheless takes up a search when Mii goes missing. The endeavour connects him with the town's folk and reveals that he is not alone.

1968年12月10日，一名假冒警察的嫌疑人谎称一辆运钞车上装有炸弹，随后开着满载日元的运钞车逃之夭夭。在此后的15年间，日本警方动员12万人以及三倍于被劫款项的经费追查凶手，却始终没有收获。刑事诉讼时效刚过，为此案赔付了50万美元的美国保险公司大发雷霆，旋即派出旗下经验丰富的日裔查勘部长武田秀哉（田村正和 饰），前往日本追查嫌疑人下落。在亚洲调查公司调查员中冈凉子（余贵美子 饰）和高原薰（段田安则 饰）的协助下，武田重新走访案发现场和相关人员，并将目光锁定在案发后不久服用氰化钾自杀的问题青年滨野健次。随着调查的进行，重重黑幕阻挡着他们的去路……
本片由著名推理作家松本清张根据真实事件创作的小说改编。