This is the issue of Catalysm where everything comes together. Spider-Man has been teamed up with the UItimates for a while and now the X-Men have made their way over. It's a very natural transition for the X-Men. It doesn't feel forced, seeing as their tie-in just came to a close, and they just made it to see the destruction Galactus has caused. It's a very nice lead in for the rest of this issue and Kitty Pryde finds she's needed in the final battle.
Kitty isn't the only character who is key to the battle. Jean Grey becomes an intricate part of the story. I complained, quite a bit, with the conclusion of ULTIMATE X-MEN because Jean was allowed to just waltz back into the X-Men after waging war on them; however, she's a huge part of this issue, and it's great to see her as a team player again. Through Jean, the reader gets to know a bit more about Galactus and why he is on Earth. Believe it or not, the reader may feel a bit bad for Galactus here. He knows he's lost but doesn't know where he is, other than on an Earth that isn't the Earth of his universe. He's weak, but still incredibly powerful compared to everything and everyone else.
Ultimate Captain America is pretty bad ass. Readers knew that the first time he let someone know that the "A" on his helmet doesn't stand for "France." (Yes, that really happened) He goes for the gold here by doing anything he can to stall/stop Galactus. The cover gives a bit away to what happens here, but not everything. Cap fights here like a champ and while it's not entirely sure whether or not he dies, it's an incredibly fun time. Bendis really knows how to make a book fun to read, even when what's happening to the characters is completely nuts and the reader thinks nothing good will come of the event.
The only real problem with this issue was that Bagley's art was a bit off here and there. There was some inconsistency within faces, even in the opening pages. On top of that, there's a whole bunch of "everyone is surprised at something" going on here. Kitty Pryde alone spends most of the issue with the look of utter shock on her face.
The last issue of this event was a bit of a bump in the road, but issue #4 really gets this story back on track. The introduction of the X-Men works well here and the scenes with Jean Grey are one of the many highlights of the issue. While Galactus is the villain here, the reader will get to feel for the character, as he's truly just lost in this world. Writer Brian Michael Bendis has crafted a very fun story with a lot of peril and suspense. The only real complaint here is a bit of inconsistency with Bagley's art, but aside from that, this was an excellent issue.