The Vale of Holocaust was a region of space, not far from the planets of Troch. It was formed by clouds of radioactive fallout, with a whirlpool at its centre. It would disable the instruments and equipment of any spacecraft entering the region.
During a space reconnaissance mission, Don Morais and Zec passed by the Vale of Holocaust when a steering malfunction caused their ship to head towards it. Unable to reverse course, they were saved at the last moment when lightning struck the ship, reversing the hull's polarity and causing them to be repelled away from the whirlpool. (COMIC: The Dalek Trap)