Prayer and ingenuity have kept the remote English convent of St. Winifred in the Fen going for centuries, but now the roof leaks, the bell tower is crumbling and rats have moved in. The Bishop's accountant wants to send the retired sisters to a home, disperse the working nuns, pull down the buildings and sell the land off as a car park. But he has reckoned without the unstoppable force that is Reverend Mother Elizabeth. With her team of ex-offenders, migrant workers, and passing strangers, she plans not just to save, but also to renew, restore and revivify the sisterhood. The gentle, witty letters of Sister Boniface, who, as newly-appointed convent shopkeeper, has a big role to play in this challenge, chart a year of the sisters' struggle as they get to grips with the harsh realities of the 21st century armed mainly with kindness and home-baked biscuits.