Let me pause for a brief moment to honour Pamela Salem as Toos, quite possibly the sexiest woman to ever appear in Doctor Who. Her facial makeup and headdress are something to behold (why does everyone on the sandminer gussy up so much when they're "at work"?), but she spends most of this episode partially disrobed and lounging around her quarters, unconvincingly fending off robots with sturdy vases. It all makes the mind wander...
One of the great Doctor-guest character duos happens during this episode, too, when D84 becomes The Doctor's de facto companion while Leela is kept busy by failing utterly to keep a close eye on Chief Mover Poul. Gregory de Polnay brings just the right amount of sympathy to the role of the undercover robot, a tough task given that D84, like the rest of his brethren, is supposed to be emotionless. However, with Chris Boucher giving him such poetic lines like, when describing a Laseron probe,"It can punch a fist-sized hole through six inch armour plate, or take the crystals from a snowflake one by one", I'd much rather have the well spoken D84 any day.
It's almost a shame that D84 wasn't kept on as a companion, in some way, as he is far better an automaton companion than Kamelion ever could be, plus much less annoying. He doesn't even have super human strength, nor is he a computing wizard, so he never would have proved too smart for the script's own good. He's even a little bit clueless - his following a skulking Doctor, who is trying to be quiet, inquiring "I heard a cry!" until he gets a satisfactory is one of the highlights of this episode.
Okay, when SV7 is looking at his master on a viewscreen, a man who is apparently in disguise, is it not immediately apparent who the person behind all the berserk robots is?