THE EVENT 20 YEARS IN THE MAKING!·WITH APPEARANCES BY EVERY AVENGER & JLA MEMBER ... EVER! THE WAIT IS OVER! The most eagerly anticipated comic book crossover of all time has finally arrived, with alternating Prestige Format issues by Marvel & DC Comics! What cataclysmic threat could endanger two universes - and dwarf the combined power of both Earth's Mightiest Heroes and the World's Greatest Super-Heroes? The world finally learns the answer in September 2003!