Always seeking a way to wreak mischief on the life of his brother Thor, Loki scans Midgard, the mortal world, searching for some way to make trouble. As his astral gaze finds the Hulk, he sees the perfect instrument. Using his powers of illusion and trickery, Loki makes it seem as if the Hulk has attacked a passenger train. Rick Jones and the Teen Brigade quickly learn of the attack, and attempt to speed the news along o the heroes of the Marvel Universe. In an attempt to keep the broadcast from reaching the Fantastic Four, Loki diverts it to one he knows Thor will hear. But in doing so, Loki has accidentally brings together some of the strongest defenders of the Marvel Universe... Iron Man, Ant Man, the Wasp, his brother Thor and the Hulk... the Avengers!