Walking with Superman: Day 229

Superman's leading a new generation of Challengers of the Unknown into the depths of the timestream, searching for their missing mentors. The trail leads them to the very end of time, where Challenger Mountain remains in a tiny pocket dimension amidst the endless entropic morass. Somewhere in this little shard of Colorado lies the key to the original Challengers' disappearance, but to get there, Superman and the young Challengers must make their way through thousands of dangerous and deadly creatures, stolen from hundreds of worlds across all time and space. Meanwhile, there's nary a star in sight, let alone a nearby yellow sun, so Superman's powers are fading fast! And when the mysterious mastermind behind this terrible temporal trap reveals his sinister scheme, it looks like the Challengers' borrowed time may have finally run out!