WWW3 - Invasion of the Dinosaurs 3

Invasion of the Dinosaurs is a particularly strong story for both Mike Yates and Sarah Jane Smith. Yates's character arc is quite interesting. He is revealed to be one those behind the dinosaur appearances surprisingly early in Episode 2 - so early that you have to wonder if perhaps Yates is spy for UNIT in a more overt example of espionage like what he did in The Green Death. When he first sabotages The Doctor's dinosaur stun gun, then, to save The Doctor from being attacked by a marauding T-Rex, reactivating the gun and using it to fell the beast, it looks like he might have been on the side of the "bad guys", but then hops back to the good at just the right moment.

Sarah is so strong in this story that she threatens to overshadow The Doctor, especially in this episode. It is she who clues into the possibility of a nuclear reactor existing underneath London, and her forthright attitude leads her to the office of Charles Grover, who promptly reveals himself to be a traitor and imprisons Sarah in the bunker. It's then Sarah who gets put aboard the "spaceship" that is setting out to find New Earth (presumably the first one of sixteen New Earths). Seldom has a companion been in the thick of the action this much since the Ian Chesterton days.

The cliffhanger revealing that Sarah is, supposedly, on a spaceship seconds after having been seen in a basement in present day London is superb. Of course, you know it's most probably going to be some sort of trick that will be explained in Episode Four, but it's one of those cliffhangers that aren't necessarily suspenseful, but turn the plot on its ear and threaten to take it in an entirely new direction come the next episode.