The 1313th Aces & Eights live in The Spire, a massive floating fortress tethered above the clouds of a flooded Louisiana. Below them, a jagged Portal pulsates over the ruins of New Orleans, vomiting out Martian Scavengers-monsters that are half-biological, half-rusted machine. During a standard suppression mission in the Honey Island Swamp, Eight 2 (Simon Smith) scans a downed creature and discovers a serial number belonging to the Ares Initiative, a human colony sent to Mars 30 years ago and presumed dead.