A young couple Mira (Abbie Cobb) and Todd (Sean Faris) hire a live-in nurse (Lyndon Smith) to be the caregiver for their sick son, only to discover that she is an "angel of death" intent on replacing Mira through any means necessary.

圣诞节前夕，一个金发美女空降邮局，她的工作是为圣诞老人回信，实现人们的圣诞愿望。有一个小女孩在信中说，希望帮她孤独的叔叔找一个女朋友，这位孤独的叔叔正是邮局的信件分拣员，由于工作接触，与神秘的圣诞女孩情投意合，小女孩也非常喜欢这位金发美女。可是平安夜却发生了误会，有情人能不能终成眷属呢？