Eden's Wake — Lynn Steigleder

Ben s best friend is killed in an underwater implosion on a dying world. Living to die again, the two men reunite and battle for an ancient artifact, a relic which will ensure this planet s survival. Ben crosses a threshold. The world he leaves doomed; the world he enters reborn. His wife, Eve, and their bumbling charge, Eleazor, follow Ben through the doorway and blindly into the void. This is Book Two in the Rising Tide series.