Aquaman: Sword of Atlantis #57 (2007)

Finding Zero
Having managed to put a halt to Krusivax and Vandal Savage's plots to cull the human population, Aquaman's attention is quickly directed back to Sub Diego. A scientist who was working in the employ of Black Manta has Cal Durham's girlfriend hostage, taunting Aquaman to come rescue her.But this madman might be the key to the questions that Arthur has lived with since he found himself in the ocean.
Release Date: 2007