Where To Stream Doctor Who Season 19 Episode 4
Castrovalva, Part Four
- Aired January 12, 1982
- 25 Min
- Rated 8.9
- Number 320 Of 700 Rated Episodes
The Doctor discovers Castrovalva is a cursive occlusion, an impossible yet manifested Escheresque environment, with all pathways, no matter which direction one goes, leading back to the same point. It is a trap laid by the Master with no apparent way out.