London. The Golden Age Retirement Home has lost some of it’s residents during a day trip to the nation’s capital. Normally that wouldn’t be anything to worry about but when it’s the Teenage Mutant Ninja Turtles’ Great Grand Daddies, and they haven’t taken their pills, you’d better call U.N.I.T.
The Brigadier’s got his work cut out for him though; Sarah’s getting spaced out watching the Discovery Channel with a French resistance fighter who can’t sing while the Doctor is busy boosting cars, stealing frilly shirts from high street shops and having a quick fumble with some old bird in a broom cupboard. Looks like Captain Yates is his only hope.