Justice League of America, Vol. 1

The alien Treasurer's hand over the new supply of Element X once the last item they have asked for - a postal clerk named George Stuart - agrees to go with them. While taking the new supply of X into the stratosphere, it explodes prematurely, injuring Red Tornado. As Batman and Elongated Man help him, the supply of X rains down across the world, seemingly transforming animals and people into monsters. Suspicious of the Treasurer's motives, some of the League follow them to their homeworld where they find them bartering Stuart to another race of aliens. Before they can act, however, they are stayed by yet another alien. Back at the JLA satellite, Hawkman delivers the news that a third of people and animals are being mutated when the satellite is attacked by alien space craft. Playing possum, the League are joined by the Phantom Stranger who plans to aid them against the aliens. On the Treasurer's homeworld, Superman and his team are informed by the new alien, the Truthspeaker, the the two alien races, Treasurer and War-Kohns, act together to find planets suffering from Element X decay. The Treasurers take payment for a new supply which is infected and mutates the population which then aid the War-Kohns as they invade.