But Castrovalva is not the haven of peace and tranquillity the Doctor and his companions are seeking. Far from being able to rest quietly, the unsuspecting time-travellers are caught up once again in the evil machinations of the Master.

Only an act of supreme self-sacrifice will enable them to escape the maniacal lunacy of the renegade Time Lord.

The TARDIS, controlled by the Master, is rushing towards Event One and imminent destruction; Adric and his computational powers are being manipulated to the Master's own ends.

But the Doctor has been weakened by regeneration and the travellers attempt to travel to peaceful Castrovalva unaware of the web that has been spun by the renegade Time Lord ...

Doctor Who - Castrovalva marks the beginning of Peter Davison's tenure of the role of the Doctor ans was written by Christopher H. Bidmead, who was script editor of the series during its eighteenth season.

Doctor Who is currently being reshown on BSB television.
 

"Recursive Occlusion. Someone's mannipulating Castrovalva. We're caught in a Space Time trap!"

Can the Doctor's regenerationreally be failing this time? It certainly looks that way as his two assistants Tegan and Nyssa help him recuperate on the tranquil planet of Castrovalva. But are things as peaceful as they seem? What has happened o Adric? What is really going on in Castrovalva? And, more importantly, where is the Master?

Running time: 97 mins approx.

Produced by John Nathan-Turner
Directed by Fiona Cumming

Originally transmitted 4 - 12 January 1982, this four part adventure marks the beginning of the Peter Davidson era for Doctor Who.