Reed and Sue Richards are vacation in the center of the galaxy so that Reed can study some unusual findings. A star goes nova and the explosion seems to reach their ship just as the send a warning to earth about Reed's findings. The rest of the Fantastic Five team head out to space to help Reed and Sue. Before they leave they warn the president.
The president alerts the Avengers about the potential disaster. They call in their reserve members, including Spider-Girl.
While this is going on Galactus lands on the Shi'ar home-world and plans to drain it of its life energies. The Shi'ar guard fight to save their planet, but are unsuccessful. Galactus next sets his sites on Asgard.