Batman investigates a murder spree that takes place on holidays.
 
This film has great animation and a solid story that is all wrapped up in a movie that pushes the PG-13 boundaries to make it almost R rated.  Honestly, DC always does a great job with giving you great animated films.   
 
FUN FACT:  Carmine Falcone sports a three-scratch scar on his right cheek. This is a reference to "Batman: Year One" comics where Selina (taking up her mantle as Catwoman for the first time) tried to make a name for herself and scratched Falcone's face while he was unconscious.