OK, so, the special effects on old Doctor Who have never been what anyone might consider “good.” The dinosaurs look really bad, especially when they open this episode by fighting each other. That said, Jon Pertwee probably deserved an acting award or two for making it look like he’s taking this stuff seriously.
After evading some dinosaurs, General Finch captures him. Finch tried to frame the Doctor for the dinosaur invasion. That didn’t work, but Finch is really part of the cabal doing the whole “erase most of humanity” plan to bring back a Golden Age. The Doctor finally outright says this Golden Age never actually existed. Thank you, Doctor.
Fortunately, the Brigadier shows up with Sergeant Benton to “arrest” the Doctor himself.
Does the Brigadier believe the Doctor is innocent? Mostly. He’s not sold on Captain Yates being a traitor until Yates shows up to hold Benton, the Doctor, and the Brigadier at gunpoint. Does Yates know what’s going on? Yes. Does he know if he’s going to survive the erasing? Nope. He says he’s unimportant. Man, that supercomputer really did a number on him. As it is, Benton and the Brigadier manage to subdue him. The Brigadier leaves Benton behind to call for reinforcements if necessary while he and the Doctor go check where the Doctor knows the underground base is.
While this is going on, Sarah Jane is back on the fake spaceship. She’s starting to convince the other people, high-handed dicks that they might be, that someone tricked them. Even Sir Grover coming over in a fake spacesuit doesn’t work out for the treacherous MP. Why not? Sarah Jane opens the airlock.
So, after the Doctor and the Brigadier get past yet another convenient dinosaur (after they even drove a jeep under one), and after Benton subdues Finch and sends in the rest of UNIT, and after Sarah Jane and the environmentalists show up to confront Whitaker and Grover over their cruel and stupid plan, do these asshats stop trying to destroy most of the human race? Nope. They flip the switch anyway.
Some people never learn to let things go.
Fortunately, even with most of the humans present frozen in time, the Doctor is a Time Lord. As such, he is somewhat immune to whatever is happening. So he just shuts the machine off and fiddles with some wires. Grover tries again, but this time Whitaker tries to stop him because the Doctor reversed the polarity. That just means rather than reversing time, Grover only sends himself, Whitaker, and console back in time to see that Golden Age for themselves.
So, what happens now? Finch is court-martialed, and Benton is happy to be a sergeant that got to lay out a general. Yates will be sent away for a psyche eval due to his UNIT service so he can then resign quietly. Sarah Jane decides not to go on the TARDIS again because it’s dangerous. You know, until the Doctor slyly tempts her with some planet full of flowers and stuff.
You know, the Doctor promised Jo a trip to a beautiful planet, and by the time the Doctor finally got there (alone I might add), the place was a hellhole he seems to have barely escaped with his life. Sarah Jane should listen to her instincts here.