Doctor Who: 5 Reasons You Need To Watch Castrovalva

2. Shows The Genius Of Adric

As the serial moved from part 3 to part 4, viewers found that Castrovalva was nothing but a mathematical recursion, or in laymen's terms, the city was a mathematical problem made into a physical form. This was all made possible through the mind of the Doctor's third companion, Adric. Adric, for those of you who are unaware, is a mathematical genius from the planet Alzarius in a parellel universe. The Master was able to use Adric both to force the TARDIS to Castrovalva (Adric appeared on the TARDIS, did some stuff on the control panel then went to help the Doctor) as well as used his mind to create the whole city and history of Castrovalva. However, Adric proved his will was much stronger than the control of the Master when he ended up causing Castrovalva to start folding in on itself, creating numerous repetitions and errors within the city. Finally, as the city itself was the creation of Adric's mind, he was the only one who could safely guide the Doctor and his fellow companions to safety from the confines of the imaginary city. Not too shabby for a companion that many people rank fairly low on their 'Top Companion' lists. Perhaps he deserves a bit more credit.