It’s the team-up you never saw coming—and will never forget! When the tyrannical Darkseid breaches dimensions in search of ultimate power, his conquest leads straight to the world of Sonic the Hedgehog. Sonic and his friends have faced mad scientists and ancient spirits, but the forces of Apokolips may be more than they can handle alone. Enter the Justice League! Superman, Batman, Wonder Woman, and the fastest hero alive—The Flash—join Sonic in a race against cosmic annihilation. Can speed and strength stop the god of evil before two worlds fall? This Free Comic Book Day special edition kicks off an epic crossover event from writer Ian Flynn and artist Adam Bryce Thomas, with a stunning cover by Pablo M. Collar. Packed with action, surprises, and fan-favorite characters, this is one collision of universes you don’t want to miss!