Batman (1940) #672
"Space Medicine" is written by Grant Morrison and drawn by Tony Daniel. Inks by Daniel, Florea, Glapion and Irwin. The Third Batman, one of a trio of homicidal maniacs disguised as the Darknight Detective, storms Gotham City P.D. and sets a torch to the place, demanding to see Vane, the commissioner of police before Jim Gordon. Gordon steps into the madman's weapon sights to save further lives and a hostage situation quickly arises.
Meanwhile, Bruce Wayne is stepping out with international pop star turned philanthropist Jezebel Jet, and contemplates the idea of finally taking the plunge into marriage. Before such thoughts can be entertained however, Bruce's alter ego must deal with the insane Bat-maniac holding Jim Gordon at gunpoint. On the rooftop where the Bat-signal burns brightly, Batman takes on his twisted doppelganger and finds the mimic more than equal to the task of battle. Amid vague hints of his mysterious origin, the villain shoots first Gordon and then Batman, causing the Caped Crusader to suffer a heart attack. In what could be the final instants of his life, Batman calls upon the most unlikely of allies: Bat-Mite!