The Fourth Dimension
Last of the Timelords
The Master seems to be a Scissor Sisters fan. He's singing along to I Can't Decide from their Ta-Dah album on the flight deck of the Valiant.
Vive La France!
"Toclafane" roughly translates into "Fool The Fan" in French. Magnifique!
Dictators love their big statues. Probably the most famous one in recent years was the statue of Saddam Hussein in Baghdad, toppled by occupying forces at the end of the second Gulf War. That was only 20ft tall though, not quite up there with a 200ft Master.
The Master has added his likeness to Mount Rushmore - joining 60ft granite sculptures of George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln. The god Xoanon did something very similar, carving the giant head of the Fourth Doctor into a mountain in The Face of Evil.
Mac vs. PC
Doherty complains about her useless computer system, saying that she misses Microsoft head Bill Gates. Bill's probably working for the Master to make his laser screwdriver Vista compatible, whilst Apple boss Steve Jobs continues to develop the iToc...
Earth was first referred to by its Gallifreyan name of Sol 3 in The Deadly Assassin (1977). It's in Mutter's Spiral, the Gallifreyan name for the Milky Way.
Who's Got Wheels?
The Doctor is not stranger to wheelchairs. He escaped from hospital in one in Spearhead From Space (1969) and used an electric wheelchair to get around the TARDIS in his weakened post-regenerative state in Castrovalva (1982).
The Master refers to the Doctor's previous battles with the Sea Devils in, er, The Sea Devils, and the Axons in The Claws Of Axos.
The Medusa Cascade
This episode marks the first mention of the Medusa Cascade, which plays a major part in Series 4.
Fact File compiled by Rob Francis.