The Threat from Beneath

The Threat from Beneath was the 11th story of the Tenth season

It was one of the few Doctor Who stories to depict a nuclear explosion on Earth. Moreover, it may be the only story where the Doctor orders a nuclear weapon detonated in Earth's atmosphere.

Plot
The Daleks destroy several Earth's satellites scanning for extraterrestrial life some time in the Cold War. As the Dalek Saucer Commander predicts, the humans react by squabbling amongst themselves. The Soviets think it's the Americans who've taken out the satellites, while the Americans believe the reverse. As both sides look for a terrestrial explanation, the Dalek saucerslips into an Earth ocean, and settles unseen on the floor.

The Doctor is called to an urgent meeting at Whitehall. In a secret facility beneath the city streets, he examines data on the exploded satellites. Admiral Dunsford claims the Soviets have nuclear-armed satellites. The Doctor pushes this theory aside brusquely. The data, he insists, support only the theory that the satellites weren't just destroyed — they were atomised. That means that Britain and the world are threatened by extraterrestrials.

Later, the Doctor — and the rest of the people who had gathered in Whitehall — receive new intelligence. An object came down somewhere off the Pacific coast of South America. The Doctor suggests it must have been a controlled spacecraft of some kind, else its impact would have created a tidal wave. This, however, the admiral and his cronies cannot accept. The Doctor fails to convince Britain's top military leaders. He leaves Whitehall, convinced it's up to him alone to stop the world's superpowers from destroying each other.

He's wrong, however. Even as he prepares the TARDIS for travel, the Admiralty have sent orders to one of their submarines in the Pacific, the HMS Pandora, to look for "green-eyed Martians" beneath the sea. The Doctor finds them first. The TARDIS lands in a quiet area of the Dalek saucer, allowing him to sneak up on the Dalek control room. He sees that the Daleks have noticed the approach of the Pandora and are taking action against it. They don't destroy it. Instead, they turn its crew into a form of Roboman. They command the crew to report "negative findings" to the Admiralty.

The Doctor, by now, is crawling around in the power conduits of the Dalek saucer. He creates a distraction by starting an electrical fire with a lot of smoke, thanks to the chemical composition of the Dalek wiring insulation. He drops down to the Dalek communication panel, where he tries to communicate with the Pandora. At first he seems unsuccessful, but he gives the Pandora new orders on the proper Dalek control frequency: they are to send a Polaris missile at a 90-degree angle, then run like hell before it comes down. The Daleks find the Doctor in the smoke and fire at him, but their aim is impaired. The Doctor runs for the TARDIS, hoping he'll get there before the missile comes down. It hits the Dalek saucer precisely. The Dalek threat ends under a huge mushroom cloud over the South Pacific.

When the Doctor returns to the Admiralty, Dunsford is in a self-congratulatory mood. The Royal Navy have saved the day! The only problem, the Doctor points out, is that he knows the Admiralty didn't send the order to activate Polaris. So if not they, who was in control of one of Britain's nuclear weapons?

Characters

 * Third Doctor
 * Dalek Saucer Commander
 * General Sanders
 * Admiral Dunsford

Continuity

 * The nuclear explosion depicted in the story was not the first TV Action would illustrate. It also wasn't the first they'd show in a story that involved Daleks and submarines. Earlier, they'd blown up Sydney with sub-based nuclear weapons in Sub Zero. This time, it's the Doctor who's actually got his finger on the button.
 * A Dalek Saucer Commander previously appeared in The Dalek Invasion of Earth.