Lying on his side on a dark summer night earlier this year, Sir David Attenborough is watching a hedgehog snuffling around an urban garden.
"I think they're lovely things," he says softly, with a chuckle.
His voice blends boyish wonder with the wisdom of his 99 years - each in equal measure.
Considered by many as the most famous broadcaster and conservationist of our time, Sir David has circled the globe for 70 years to show us the brilliance of the natural world.
Now, in a new one-off documentary, he has come home - to London.
