To the outside world, the residents of Pepys Road in south London have it all. House prices have rocketed, creating a street of multimillion pound homes – until a mysterious note bearing the words ‘we want what you have’ is dropped through every letterbox. Who has sent the message? And why are they watching the residents?

Petunia has lived all her life on the street. She is growing increasingly worried about her dizzy spells, but doesn’t want to turn to her daughter Mary for help. Meanwhile, Roger, banker and supposed family man, is hoping that this year’s bonus might bring him and his wife Arabella, played by the fabulous Rachael Stirling, happiness – or at least be able to cover the cost of all the renovations he’s been doing on the house.

Before long the ripples caused by the anonymous note will have touched every corner of the community – and the residents of Pepys Road will see their lives transformed…

“Capital” starts on Tuesday 24 November, 9pm, BBC1

Also catch Rachael in BBC4′s brilliantly sublime series “Detectorists” on Thursday nights.