Who or what is X.E.R.O.?! Unable to maintain the human guise of Aaron Stack, X-51 finds himself a fugitive from the law! And to add to the heat, fanatical federal agent Peter Gyrich and a foe of the X-Men (whose identity we'll keep secret for now) also want to pull the plug on our beleaguered Machine Man! And wait'll you see Xero, the technological terror that they intend to unleash upon him! What strange and sinister connection links him to our beloved X-51?!
The Brotherhood & Dr. Stack appear in flashback.