The secret of the Trench revealed! Where did these cannibalistic sea creatures come from? What fuels their monstrous hunger? Why have they chosen now to invade the surface world? To unravel the mystery of the Trench, Aquaman must seek help from the last person on earth he ever wanted to see again.

Aquaman and Mera visit Dr. Stephen Shin with one of the creatures. By studying the being's glands, Shin determines that this race came from the Mid-Atlantic Ridge in the Trench. Dr. Shin wants to keep the trench being but Aquaman refuses and then as the sea king and Mera are leaving, Shin makes on more attempt to find out where Atlantis is.

On the way towards the home of the trench, Aquaman wonders if this race is on the verge of extinction, because of their need for food. Mera believes they are monsters but Aquaman thinks they are struggling to survive and the issue ends with the heroic couple descending into the abyss.