After the X-Men escape from Bastions base, Wolverine makes a huge discovery and reveals the secret of the Prime Sentinels!
Having escaped from Bastion's New Mexico base, the X-Men cross the desert sands till they reach a trailer encampment. They find one inhabitant, a former stunt pilot, nicknamed Mustang, who had lost the use of his eyes and legs in a crash. He and the other campers who reside there are patients of Dr. Prospero at a clinic nearby, where major injuries are healed.
They all bed down for the night, but once everyone is asleep, Logan heads to the clinic to check it out. The next morning, the others learn what Logan discovered: the clinic is repairing injuries with cybernetics, that transform the unwitting patients into Prime Sentinels under the control of Operation: Zero Tolerance.
Suddenly, OZT aircraft are seen approaching, as well as a busful of the camper returning from the clinic. Mustang hides the X-Men, as above, Bastion gives the command to activate those patient farthest along in the transformation, in case they are near any mutants. At the same time, Mustang warns his fellow patients about what he's learned.
In Washington, D. C., Senator Robert Kelly decides to pull support for Zero Tolerance, and contacts S.H.I.E.L.D.