This volume reprints Marvel Comics' Annihilation issues #1-6, Annihilation: Heralds of Galactus #1-2, and Annihilation: The Nova Corps Files.
This is the climax of the Annihilation `event' - which was an experiment involving ALL of Marvel's `cosmic' characters, to see if they could carry an ongoing series. This event pulled in everyone and his long-lost brother (or it will do in subsequent X-Men sequel...) from Galactus and his heralds to Thanos and the latest Captain Marvel and Quasar at one end of the spectrum, to Rocket Raccoon and Cosmo the Cosmodog at the other, as Annihilus invaded the positive universe, destroying the remains of the Skrull Empire in the process, and severely damaging the Kree Empire before he was stopped by Nova. Yes, that Nova, the teenaged Green Lantern knockoff from the 1970s. He went on to star in his own cosmic series, just to show that Steve Englehart's comment, made back in the 1970s, that there were no bad characters, just bad writers, has been proven true yet again. Anyway, here the heroes have been driven to the verge of defeat, before being dropped off in the lay-by of despair. However, Thanos, who has turned Galactus into a cosmic power battery for Annihilus, is not totally committed to the Dark Side, and decides to free Galactus, but unfortunately not before Drax the Destroyer kills him, but when has death ever got in the way of Thanos...
This is an incredibly entertaining comic, with very good artwork and is an excellent addition to Marvel's cosmic mythology, and proved to be the springboard to further cosmic series building on from here.