Castrovalva

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

This historic, four-part adventure marks the debut of the Peter Davison era for Doctor Who.  The Doctor’s legendary regeneration may finally have failed him!  His trusted assistants Tegan and Nyssa try to nurse him back to health on the tranquil planet of Castrovalva.  But things may not be as peaceful as they seem. 

What is really going on in Castrovalva?  What has happened to Adric?  And more importantly, where is the Master?  Doctor Who must discover the answers, even as he struggles to regain his strength!

• It is said that this story is, at least in some small part, inspired by the artwork of M.C. Escher.

• Although "Castrovalva" is the first adventure with the 5th Doctor, it was the fourth story to be filmed.  This was done to give Davison a chance to adjust to his role before he had to perform out of character (due to his regeneration).  An alternative explanation surfaced later stating that the original opening story was scrapped at the last minute and "Castrovalva" inserted in its place.  To give the production crew more time to prepare, filming was pushed back making "Four to Doomsday" the first one to be taped. 

• This story finishes the loosely arced Master Trilogy.  The first story was "The Keeper of Traken" while the second was "Logopolis."

• Watch for Davison's amusing impersonations of the 1st, 2nd, and 3rd Doctors.

• Playing Mergrave is none other than Michael Sheard.  Sheard's first role in Doctor Who was in the 1966 Hartnell story "The Ark" as Rhos.  5 years later Sheard would return as Dr. Summers in the Pertwee story "The Mind of Evil."  Sheard would again appear in Doctor Who, this time as Lawrence Scarman in the classic Tom Baker story "Pyramids of Mars."  Next up was the part of Lowe in "The Invisible Enemy."  4 years after his appearance in this Davidson story he made his final appearance in the 1988 Sylvester McCoy story "Remembrance of the Daleks."  He's a busy man...