Aston (Robert Shaw), a quiet, reserved man, lives alone in a top-floor cluttered room of a small abandoned house in a poor London district. He befriends and takes in Mac Davies (Donald Pleasence), an old derelict who has been fired from a menial job in a café. In time Aston offers him a job as caretaker of the house. Aston's brother, Mick (Alan Bates) - a taunting, quasi-sadist - harasses the derelict when his brother is away, countermanding his orders. Eventually Aston, himself irritated by the cantankerous old man, puts him out.
八公（Forest 饰）是一条谜一样的犬，因为没有人知道它从哪里来。教授帕克（理查·基尔 Richard Gere 饰）在小镇的火车站拣到一只走失的小狗，冥冥中似乎注定小狗和帕克教授有着某种缘分，帕克一抱起这只小狗就再也放不下来，最终，帕克对小狗八公的疼爱感化了起初极力反对养狗的妻子卡特（琼·艾伦 Joan Allen 饰）。八公在帕克的呵护下慢慢长大，帕克上班时八公会一直把他送到车站，下班时八公也会早早便爬在车站等候，八公的忠诚让小镇的人家对它更加疼爱。有一天，八公在帕克要上班时表现异常，居然玩起了以往
