Dawn of the Dead Man!

Teaser: Batman joins forces with Kamandi the Last Boy on Earth and his companion Dr. Canus to secure some antibiotics while evading a group of Rat Men.
Main Plot: When he ends up buried alive by Gentleman Ghost, Batman uses a special meditation to leave his body and has an encounter with Deadman. With some tricks learned by Deadman, Batman has Green Arrow and Speedy dig out his body before it runs out of air so they can stop Gentleman Ghost from raising an army of the dead.