In the distant future, the Doctor, Sarah and Harry find a space station preserving the future of mankind. But the insect Wirrn have got there first...

In 1939, Sir Robert Thorndyke takes aim at Adolf Hitler with a high powered rifle, but the shot misses its mark. Captured and tortured by the Gestapo and left for dead, Sir Robert makes his way back to England where he discovers the Gestapo has followed him. Knowing that his government would turn him over to German authorities, Sir Robert goes underground in his battle with his pursuers.

Viola and Sebastian are lookalike twins, separated by a shipwreck. Viola lands in Illyria, where she disguises herself like her brother and goes into the service of the Duke Orsino. Orsino sends her to help him woo the Lady Olivia, who doesn't want the Duke, but finds that she likes the new messenger the Duke's sending. Then, of course, Viola's brother shows up, and merry hell breaks loose. Meanwhile, Olivia's uncle and his cohorts are trying to find some way to get back at Olivia's officious majordomo, Malvolio.

The TARDIS narrowly avoids becoming engulfed in a cobwebby substance in space. It arrives in the London Underground railway system, the tunnels of which are being overrun by the web and by the Great Intelligence's robot Yeti. The time travellers learn this crisis was precipitated when Professor Travers, whom they first met in the Himalayas some thirty years earlier, accidentally caused one of the Yeti to be reactivated, opening the way for the Intelligence to invade again.

In 1940, the Royal Air Force fights a desperate battle against the might of the Luftwaffe for control of the skies over Britain, thus preventing an attempted Nazi invasion.

Gawain was a squire in King Arthur's court when the Green Knight burst in and offered to play a game with a brave knight. Gawain journeys across the land, learning about life, saving damsels, and solving the Green Knight's riddle.

A couple finding their old car worthless at a scrapyard tries to abandon it in another area, only to keep seeing it again on streets that are getting closer to their home.