For my reviews of issues one and two click here and here. So this issue starts out with Miles and Peter being confronted by Ultimate Mysterio who is responsible (apparently) for this whole inter dimensional mess. After our Spider-men fight their way through illusions of their respective rouges galleries. They defeat Mysterio, or rather the remote control Mysterio robot he was piloting from a safe location and of course it explodes. Miles wakes up to find the Ultimates there. Peter however isn't sure if this Ultimate universe is real or just some of his Mysterio's typical bullshit. So he goes to find his apartment which is a store front here and borrows the store owners iPad to surf the net. He find info on Ultimate Spider-man and his death and seeks out Ultimate Universe's Aunt May. He finds May and Gwen and they figure he is just some asshole mocking her nephew until he unmasks and the last panel is their shocked expressions.
There isn't much I can say here that I haven't said about the last two issues. If you enjoy Ultimate Spider-man either before or after Peter's death you will probably like this series.