Castles in the Sky

Another one of those 'the story of...' 90-minute dramas that the Beeb does so well.  OK so they take a few liberties with the truth for the sake of dramatic tension or humour, and the 'eureka!' moments are cheesy, but the performances are solid (with the exception of Eddie Izzard's Scottish accent wandering across the Atlantic and back) and the science of radar is explained for dummies.  There is apparently evidence that people perform best under pressure, and the threat of Hitler's Luftwaffe brought out the best in weatherman Watson Watt and his team.  Despite prejudice from the toffs, the sorely tested patience of loved ones and the political infighting of Churchill, Tizard and co. they invent something that can detect enemy planes early enough to scramble aircraft effectively.

And the rest, as they say, is history.