Ex-Marine, Zeke Callaghan is befriended by a lone alien and two partially sentient AIs who save his life. Life on Earth develops quickly as alien technology is introduced along with a warning of an apocalyptic threat to all humanity. The Nubl, a warfaring artificial lifeform views biological races as infestations and is set to annihilate humanity when it arrives. The world will never be ready, but there's always a chance.
At the same time Zeke is physically changing. A wartime surgical implant is forcing a mutation to his DNA. One of the alien AI also becomes infected when it is contaminated with Zeke's DNA. The physical changes in them both are unexpected.