The Legion of Super-Heroes call in the reinforcements against Superboy Prime and the Legion of Super-Villains as the Crisis of the 31st Century continues. While Superboy Prime comes face-to-face with the last of the Green Lanterns, Brainiac 5 and XS attempt to ignite an electrical storm using the lightning rod, which is destined to turn the tide of the war. And what are Polar Boy, Dawnstar and Wildfire up to in the 20th Century?