Geoff Johns and George Perez continue crafting the Crisis of the 31st Century! As Superboy-Prime leads the Legion of Super-Villains against everything and everyone inspired by the legacy of Superman, the Legion of Super-Heroes are forced to call for help from beyond their world. Meanwhile, contingency plans are created by Brainiac 5 as he attempts to overcome Colu's devastating betrayal, Dawnstar and Wildfire pull off a startling rescue, but at a horrible cost to the universe, and Saturn Girl uncovers the source of the Legion's troubles.
Superboy Prime has finally done it, taken a life of a Legionare. And the Legion will stop at nothing to avenge their fallen comrade. As this worlds Legionaires stand against Superboy Prime, Brainiac Five brings forth another team from another universe. Furthering their sides chances at winning.
Who is the person Mon-El and Shadow Lass bring their fallen comrades remains too....and will he ever help them?