The Challengers are back to confront mysteries that defy time, space, and everything we think we know! The Challengers of the Unknown are back, and this time, the stakes have never been higher.As the mysterious Darkseid shockwave rips through the DC Universe, reality itself begins to unravel.Ace Morgan, June Robbins, Prof Haley, Red Ryan, and Rocky Davis have been called to investigate the Watchtower s cosmic rifts alongside the Justice League.But when a sinister enemy from their past emerges, the team is thrown into a desperate race to seal the fractures that threaten the galaxy.Their odyssey takes them from outer space to the deepest parts of Earth s oceans, where unimaginable dangers await. Are the Challengers up to the task, or will the unknown prove fatal? Challengers of the Unknown is not only a crucial revitalization of classic DC characters created by the legendary Jack Kirby, it s also a key companion to flagship series Justice League Unlimited and a major part of DC s bestselling All In initiative!