First off, I'd like to apologize for this review being so late, but my local comic book shop sold out of this issue immediately and I didn't track it down until today. I'll try to review the 5th issue by tomorrow(or maybe even later tonight if I'm feeling really productive).
Anyways, on to the review. Obviously I've been loving Aquaman so far, and this issue wraps up "The Trench" arc.
In this issue, Aquaman descends into the abyss for his final showdown with the cannibalistic trench creatures. One thing that really impressed me with this issue was how sympathetic the creatures turn out to be. You can tell that they're somewhat sentient and that they're dying out; having exhausted their food supply. Aquaman tries to save the humans they abducted, but doesn't want to wipe out an entire species in order to do so. Johns handles this dilemma really well; there's no easy fix to this, Aquaman actually has to make the tough choice.
We also finally get the whole story on the trench creatures. Well, maybe not the whole story, but its still satisfying. They need people to feed to the queen, who then gives birth to new trench creatures, kind of like "Alien". Ivan Reis' art really shines in this issue, which contains multiple splash pages of the enormous trench queen. Arthur has to battle the creatures and their queen so Mera can escape, so we some cool action for the finale of the arc.
There's also a great, poignant scene in which a little boy tells Aquaman that he's now his favorite superhero; a great conclusion to the whole, "how's it feel to be nobody's favorite superhero?" theme that was established in the first issue. I also like a lot of the things that Johns sets up with this arc; Aquaman feeling really guilty and conflicted, the mystery of the Atlantean craft, and Aquadog!
Overall, this was a great conclusion to the arc, and begins to establish threads that will be carried on throughout the series.
9/10