A true story of a family and town's effort to save a beloved and heroic dog named Semper Fi. The father, a Captain in the US Marines and his homemaker wife, contend with the "not so earth shattering" problems of their twin, fifteen year old daughter and son as well as the antics of their precocious six year old daughter. Their lives tumble along, as most families do, until they must face the grave diagnosis of their faithfully and very loved Golden Retriever, Semper Fi. The family cannot afford the expensive surgery the dog needs. The children jump into action with a plan, spear headed by the fifteen year old daughter. They plan a community yard sale, donating all of their most prized possessions. The family's grumpy neighbor plays an unlikely and unexpected part in the ultimate success of the fund raising. Before Semper goes in for his surgery, he displays a heroic act that almost ends his life. The story unfolds during the holiday season.
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
