Humans are cast into the deep sea, surviving by submarine. Luther Voss, trapped in D-99, is humiliated by Zane Wilson. He awakens Abyssal Echo, upgrades D-99, recruits Kira Iron. Voss faces Zane Wilson, Jasper Hale, Rex Holt, Elara Hart, Brewster Kane, counterattacking as he discovers "deep sea survival" is a Mech Collective screening experiment, treating survivors as energy. Voss unites survivors, frees humanity, establishes independent survival order, broadcasting new era.