[Batman] Supernatural Gotham

Mermaids! Damian and the cop! Dick's story.

Dick Grayson is a police officer with the Gotham City Police Department. One day, he shows kindness to a lost boy on the street, and from then on, he steps into an underground world he's never known. With the disappearance of Gotham's dark underground king, all kinds of monsters begin appearing and committing all sorts of crimes. Damian, who aspires to become the next emperor, and Dick embark on a secret mission to capture and subdue them. As they delve deeper into the underworld, a corner of long-buried cases begins to come to light, and Damian and Dick's relationship heads toward an uncertain future... Can they solve all of this?