When a teleportation accident goes badly wrong, Nyssa finds herself stranded on the freezing slopes of the Swiss Alps in 1963. But is it mere coincidence that she finds shelter in a snowbound school haunted by a malevolent poltergeist?
When the Doctor arrives, Nyssa and the other inhabitants of the school soon discover that the ghost is merely part of a darker, deeper and more deadly game involving rogue psi talents and something else... something not of this Earth.
Written By: Andrew Cartmel
Directed By: Gary Russell
Peter Davison (The Doctor); Sarah Sutton (Nyssa); Peter Jurasik (Lt Peter Sandoz); Liz Sutherland (Alison Speers); Sally Faulkner (Miss Tremayne); Hannah Dickinson (Mlle Maupasant); India Fisher (Peril Bellamy); Chris Webber (Harding Wellman); Andy Coleman (Commodore); Nicky Goldie (Empress)