JLA A WORLD WITHOUT GROWNUPS TP

The miniseries that brought together the heroes who would form DC's Young Justice!  The Earth is mysteriously split into two seemingly identical spheres, the only difference being that one is inhabited by the world's adults; the other, its children.  Can the heroes of the JLA or the future members of Young Justice find the solution?  And does Billy Batson hold the key in the utterance of a single word?  Plus, this collection reprints Young Justice: The Secret #1.