QQQ4 - Frontier in Space 4

Escape update: The Doctor and Professor Dale are "rescued" by The Master from their sabotaged escape attempt, but then held captive and interrogated by the prison governor before eventually being handed over to The Master. Then, The Doctor joins Jo as captives aboard The Master's ship. After an only partially successful escape attempt by The Doctor, the Draconians board the ship and take The Doctor, Jo, and now The Master prisoner by the end of the episode. After four episodes, The Doctor and Jo have enjoyed precious little freedom...

After the early prison scenes, and the proceedings late in the episode when the Draconians take over the ship, this episode predominantly features just three characters - The Doctor, Jo, and The Master, and the main set piece is The Doctor's gradual escape and Jo's (and Katy Manning's) improvised to keep The Master from discovering their plan. It's a rare throwback to the minimalism of the William Hartnell days in a story designed (in part with the following story, Planet of the Daleks) to emulate the epic The Daleks' Master Plan from 1966.

I'm not entirely sure of the science in this episode, though. The Doctor manages to sneak out of the airlock and space walks, while the ship is hurtling through space, around to the top of the rocket so he can enter via the bridge. However, the stars aren't moving in the background, and the when the ship has to make a sudden course correction, the worst it does for The Doctor is shove him off the ship and out into space about 20 feet. Perhaps there's some sort of forcefield around the ship that keeps whatever is within the proximity of the ship safe and close for spacewalks? At least the Kirby wires on Jon Pertwee aren't visible...yet.