Young Mary Newton, born into a large Irish family in a small Watford semi, is always getting into trouble. When she isn't choking back fits of giggles at Holy Communion or eating Chappie dog food for a bet, she's accidentally setting fire to the local school. Whilst money is scarce, these are good times, and everything revolves around the force of nature that is Theresa, Mary's mum. But when tragedy unexpectedly blows this world apart, a new chapter in Mary's life opens up. She takes to the camp and glamour of Harrods window dressing like a duck to water - and Mary, Queen of Shops is born...