Image © DC Comics, Inc.
There are lots of clues as to who the big guy is on the cover. The story title might also help, “Olympian.” I guess I wasn’t really trying too hard, I didn’t figure it out until the last page.
Arthur Curry has lost his trident, and the person who has it is going to use it to unlock a long-barred gateway and unleash horrible creatures. They are pretty horrible, actually, good job there on the art and writing. While Aquaman tries to sort that out, Mera is attempting to deal with politics in Atlantis, and meeting lots of resentment. Most of the issue focuses on Aquaman fighting monsters, though, not a bad place to focus. Nice job by everyone involved.