 At GenCon 22 in 1989, Erick Wujcik introduced James Wallis to Kevin Siembieda of Palladium; the result was Wallis' entry into the world of RPG supplement publication through "Mutants in Avalon" (1990).The storyline of "After the Bomb" introduced a post-nuclear warfare setting, centered on the Eastern United States, where most of the area is populated by mutated animals and they form the predominant societies, as opposed to the setting of "Teenage Mutant Ninja Turtles & Other Strangeness" where mutants live on the fringes of human society.