The last issue introduced us to a new character in the Ultimate Marvel Universe: Ultimate She-Hulk. Her alter ego Jennifer Walters made an appearance a few issues back leading fans to speculate when they would see She-Hulk.
The issue begins with yet another flashback. Lindelof has done one in almost every issue now, first from Wolverine's, then Hulk's, and now Betty Ross. Fans who only buy the book will be disappointed to see that the two titular characters only appear on a few panels.
Betty Ross, as some fans will know, is the Hulk's love interest. She's the only person that can calm him down. In the Ultimate Marvel Universe, she is the reason he became the Hulk and killed hundreds of innocent people.
Jennifer Walters is also a prominent figure in this issue as well. Though there is no mention of her being related to Bruce Banner in this Universe (in fact at one point she states that she think he's cute). Instead of a lawyer, Walters is now portrayed as a scientist of S.H.I.E.L.D. She requests the Hulk serum believing that she can make it better (The power of the Hulk, but without the rage). There is much character development between Walters and Ross as the two banter back and forth throughout the issue.
The twist at the end (SPOILER ALERT) is that Ross leads Nick Fury to believe that Dr. Walters is using the Hulk serum to sell to the Chinese, and when all of S.H.I.E.L.D. comes down on Walters, Ross uses the newly developed Hulk serum on herself, becoming the Ultimate She-Hulk.
The story is now beginning to come together nicely. There are some great and funny moments in issue four (The Star Trek bit). Another moment that I thought was brilliant was the scene with Ultimate Steve Rogers and Tony Stark playing table tennis. During the game, they reference the Civil War. The Civil War was a Marvel crossover event in the mainstream universe that tore the heroes apart. Captain America and Iron Man took opposing sides. The reference pokes fun at that as in this universe, their viewpoints are reversed.