The crew arrives at Space City where Blake seeks contact with the criminal organisation Terra Nostra as possible resistance allies, but their leader Largo may have loyalty to the enemy. Meanwhile, an alien entity takes possession of Orac through his dimensional logic circuits and disrupts Cally's empathic powers driving her to madness. Blake and his crew then rush to the desert planet Zondar to seek out the heavily guarded source of the drug known as "Shadow" which is the basis of Terra Nostra's power and the only help for Cally.

Guest Stars: Karl Howman (as Bek), Adrienne Burgess (as Hanna), Derek Smith (as Largo), Archie Tew (as Enforcer),Vernon Dobtcheff (as Chairman)