Name of classic Doctor Who episode where The Doctor is stuck in the TARDIS?

Question

I remember an episode of the classic Doctor Who series where the TARDIS materializes inside itself, and when The Doctor tries to leave it, he finds himself back inside. I remember that he keeps going further inside the TARDIS to try to escape it, and each time, the console room gets darker and darker. Can anybody tell me which story this was? I am relatively certain that it is a Tom Baker (4th Doctor) episode. Thanks so much!

Answer 1

Yes, it was "Logopolis". I can't really add anything to what Artemis has said, but see link below for the official BBC guide to the episode.

Answer 2

The episode is called Logopolis, which was Tom Baker's final story as the Doctor before he regenerated into Peter Davison, and also introduced Tegan as the Doctor's companion and a newly regenerated Master portrayed by the late Anthony Ainley.

shown Feb - March 1981

Answer 3

Oooh, that's one of my favourite episodes!! It's called 'Logopolis' and it was Tom Baker's last story as the Fourth Doctor.  It was first aired in 1981 & it was a great story.  Actually it was on the Sci-Fi Channel today in the UK ; )

The bit when the Doctor and Adric keep going further and further into the TARDIS was almost at the start.  The Doctor decides to repair the TARDIS's chameleon circuit and in order to do this, he intends to materialise the TARDIS around a real police box (thus disguising it), and then obtain its precise measurements in 37 dimensions. With these measurements, he will have the inhabitants of the planet Logopolis produce a mathematical calculation — a block transfer computation — to reset the circuit. However, the "police box" he materialises around is actually the TARDIS of the Master, who has survived their encounter on the planet Traken. When the Doctor materialises around the Master's TARDIS, a recursive loop of TARDISes within TARDISes is formed.

I LOVE that episode!! : )