The Airzone Solution takes place in a future Britain where pollution has reached a point where the populace must often wear filtration masks when they venture outside. AirZone, a powerful corporation, signs a lucrative deal with the government to deal with the problem. The public is told that AirZone plans to build giant filtration plants to clean the atmosphere, but environmentalists are skeptical, especially when people begin dying and disappearing around AirZone facilities.

The Devil of Winterborne has only recently been exorcised by P.R.O.B.E. but when the body of it's last victim goes missing and a black magic grimoire goes missing from a local museum, Liz Shaw begins to wonder if the ghosts of the past have actually been laid to rest. As she revisits Winterborne School, Liz becomes convinced that the festering evil is once again attempting to exert it's influence. Liz is forced into an uneasy alliance with the now disgraced former headmaster of the school, Gavin Purcell as she must overcome her own emotions to fight the ancient evil that haunts Winterborne.