From the pages of DARK NIGHTS: METAL! Challengers Mountain has returned to the DC Universe and chosen a new team of explorers! Five misfit strangers are given a second chance at life, but only if they obey the orders of the mysterious Professor and execute deadly missions in the most unexplored corners of the multiverse! And if the new Challengers of the Unknown fail…it will be more than just their own lives that hang in the balance!