20TH ANNIVERSARY OF THE 1ST APPEARANCE OF THE SLITHEEN! Something more terrifying than mere criminals lurks within the space prison of Panotoplis. Can the Doctor and Felik be saved from possession by an evil alien entity and how can a lone Adipose defeat an invisible enemy?
The grand finale! The entire journey has led to this point, as the Doctor and Belinda face the sinister Warden. What is his staggering secret and can the time travellers do the impossible and break out of his inescapable prison?
