When Holly is a child, she wishes to find true love. She gets a snow globe that says she will find it within 20 years. 20 years later, Holly is a lawyer and still single even though her ex-boyfriend, Ted, reappears eagerly cheered on by Holly's sister. One day, however, the doorbell rings and there is a man with a Christmas tree. For various reasons, Holly immediately becomes convinced that this is the love that was promised 20 years ago.
It's like they didn't put any effort at all into making this movie the least believable (as believable as it could get with a story like this).