In a tragic case of mistaken identity, Ironhorse kills college student Sarah Cole, believing she is an alien. Deeply shaken by her death, her grief-stricken husband Martin, is bent on avenging his wife's death.
Nearby, the aliens are finalizing plans to mass produce a laser weapon designed to destroy humans. Rubies are the only crucial, missing ingredient needed to make the weapons operational. As a guilt-ridden Ironhorse continues to withdraw deeper into himself, Harrison alerts General Wilson, who orders the colonel to take some time off. But while travelling to a remote vacation spot, Ironhorse is ambushed and kidnapped by Martin Cole, who plans to execute him for his "crime."
Meanwhile, Norton begins picking up new alien transmissions which seem to coincide with a series of armored truck robberies, in the area, although the team can't figure out why the aliens are gathering money. What they don't know is that the invaders have contacted a source to purchase the rubies they need - and all they lack is money. To that end, the aliens plan to rob gold from the armored truck headquarters.
Tracking the latest transmission to Sacramento, Harrison, Suzanne and the Omega Squad attempt to disrupt the newest alien plot. In the meantime, Cole cannot bring himself to kill his captive and after Ironhorse explains the alien threat, the two men race to join the team in their latest battle. Upon their arrival, Ironhorse and Cole discover that the aliens have outsmarted the team and are making their escape with the fortune in gold. Luckily, Ironhorse and Cole are able to stop the culprits by detonating a special device armed with explosives.