Whats 50-feet-tall, nearly indestructible, and on a rampage through New York City? Iron Man calls it Ultimo... but to the members of Power Pack, its just another super-jerk trying to ruin their day off! And while our young heroes join forces with everyones favorite armored Avenger to bring down this mega-sized metallic monstrosity, are they missing something far more sinister going on behind the scenes? Does the action ever end?!? Not for Marvels youngest heroes!