In case your wondering what happened in part one and two, check out these links:
So, The story
It starts with a bit of an explanation as to why Gabriel wants to kill his half brother Harry so much. In his childhood, Gabriel grew up, not being loved by his father. He constantly heard his father talk about Harry and didn't give much attention to himself. Naturally, Gabriel began to despise Harry. He concluded that killing Harry would cause his father to love him more.. and so begins the story.
Harry in the meantime has been hiding over at F.E.A.S.T, helping Aunt May with things. Everyone else, including Peter has been looking all over for him since he gave Norah the story to publish. One day, the FBI appear at the F.E.A.S.T asking to speak with Harry. Aunt May calls Peter to come over and explains that Harry has been there.
Peter arrives as Agent Owen is showing Harry a clip from the day he was shot. The clip implies that the American Son and Gabriel are the same person since the American son only appears 4 minutes after Gabriel leaves the store.
Meanwhile, the American son take Norah someplace safe, telling her that Gabriel will be coming after her soon. As soon as he puts her down however, he has a personality switch. The American Son takes off his helmet and appears to be Gabriel. Gabriel, not aware of what has happened starts lashing out at Norah. Norah witnesses Gabriel talking to the suit.
In no time, Spider-Man and the cops arrive at the scene. Spidey goes in first and witnesses the American Son back in costume. Norah updates him on what just happened. Spdey starts fighting the American Son, who maintains his innocence until Spider-Man breaks his helmet. At this point, Gabriel regains control of himself, and Harry walks in on the scene.
With the suit, and his own mind in control, Gabriel proceeds to kill his half brother who has conveniently entered in at the wrong time.
There really isn't anything too special about this miniseries so far. If anything, we definitely get to see more screen time of Harry and Norah. Obviously, like everyone else, I have been wondering where the Stacey kids have disappeared to since BND. It would really kick ass if Gabriel's sister suddenly appeared into the picture.