Invaders From Beyond!!!
The alien invaders have set up advanced devices to collect data on the inhabitants of Appalachia. A mysterious ally named Homer Saperstein has remotely disabled the force fields surrounding these P.R.O.B.E.s and requests that the Vault Dwellers destroy them. Meanwhile, the UFO above will beam down alien soldiers to defend their technology.
Repel wave after wave of aliens and defeat their leaders. When the P.R.O.B.E.s are destroyed, the General Zeta will teleport down with the full force of the cosmos. Defeat him to send the invaders into retreat.