Night of the Batmen!

Teaser: Batman and The Vigilante have a showdown against some gangsters, and Vigilante sings throughout the fight.
Main plot: Batman is hurt after helping Aquaman, Captain Marvel, Green Arrow, and Martian Manhunter prevent Kanjar Ro from destroying a planet and hospitalized. Aquaman reveals Batman’s condition in his new memoir. Aquaman, Captain Marvel, Green Arrow, and Plastic Man wear his costume and go to protect Gotham City from criminals like Deadshot, Cavalier, Babyface, Killer Moth, Sportsmaster, Fun Haus, Penguin, Bane, Blockbuster, Solomon Grundy, Killer Croc, and Catwoman who are on a crime wave after hearing Batman is out. When Joker ends up taking the four of them down, Batman must evade the care of Martian Manhunter to stop Joker’s plot.