This is a comic series.
A serial killer named Hog gets mutated by Joker, but it results in tragedy.
Black Mask unleashes Hog on Nightwing.
Prometheus attacks Batman for revenge, but Joker interupts it.
Prometheus gets murdered by Joker, but Hog is loose so to save Gotham Batman & The Clown Prince of Crime must team up (the tragedy!) to save the city.