Four To Doomsday

Look closely at the Chinese Dragon to spot the dancers underneath, dressed in their authentic Ming Dynasty jeans and T-shirts

In the room where the TARDIS is when something visits it, not the crew or the Doctor, a member of the studio staff is seen hiding behind a crate in the foreground.

The scene with the Doctor space-walking and using a rebounded cricket ball to propel himself back to the TARDIS would have Isaac Newton spinning in his grave! The Doctor couldn't have been propelled backwards that fast by such a relatively small object as a cricket ball. If the Doctor were to actually try it, after releasing the ball in the first place, he would have started moving backwards by the action of throwing the ball. [Newton's Third Law] And not just moving in a straight line, he would have spun backwards in a slow cartwheel as a result of pitching the ball cricket-style, as he did. Assuming he was lucky enough to get a perfectly perpendicular bounce from that spacecraft, the ball would have caught up with him, impacting with whatever part of his body was facing that way at the time, increasing the rate of his spinning motion.

Tegan's sketch of "Earth fashions" is very quick. If she was that good then becoming an air hostess was a waste of her talent.

Although it was the second to be shown this was the first Doctor Who programme filmed by Peter Davison.