Fathom — Michael Lane Turner

Years ago a ship disappeared with its full complement of passengers and crew. Then it re-appeared -- with one new (unnoticed) passenger. Adopted by Air Force Captain Matthews and named Aspen, that passenger has now grown up, finished a PhD in Ocean-biology, competed in the Olympics... lived a full life among the surface-dwelling human race.

But not even she knows that she is NOT a human. She's a member of the ocean-dwelling Blue. And the Blue are not happy with what the humans are doing to the Earth.

Collects the first major storyline of the first volume of Michael Turner's FATHOM (Top Cow, issues 1-9 plus issue 0 and the rare preview).