One last gift

"Cassie and Tom lost their parents at a young age and relied on each other--as well as a community of friends--to get through it. Especially Tom's best friend Sam, who always made sure Tom and Cassie were surrounded with love. But now, twenty years later, Cassie has lost Tom as well. And in a way, she's also lost Sam; over the years they've drifted apart, and now the man she always had a crush on is someone she doesn't even recognize anymore. She's never felt more alone. Then she finds an envelope with her name on it, written in Tom's terrible handwriting, and she knows immediately what it is. It's the first clue in the Christmas scavenger hunt Tom made for her every year"--