And it's a Psych crossover, people! It's a case story, gives Nate some backstory, gets inside his head, and it works so well. So much fun!
Abnormal Psych*.
Even if you're not particularly fond of Nate, you should read it just for the sheer glee of watching Sam trying to cope with Shawn. Seriously.
*The title just keeps making me grin at its aptness, too.