BATMAN EUROPA #2 (OF 4)
The mystery deepens and the stakes get higher. Forced to work with his greatest foe, The Joker, Batman reaches Prague just as the virus he's been infected with starts to affect him. While the Czech version of Mardi Gras is in full swing, Batman and The Joker search for the mysterious Trojan Horse, a man who knows the secrets of the Colossus virus...but they'll find more than they bargained for!
AMAZING SPIDER-MAN #1.1