T he scene is the convent garden of a closed order of nuns, the place is somewhere in the UK with a maelstrom of social problems – which, let’s be real, could be any of it. Keeley Hawes’s Anna, a nun, isn’t self-righteously cloistered; she makes regular forays into the real world to do good works at food banks. But she’s not of this world. She moves with such unobtrusive poise it takes a beat to work out what it reminds you of: obedience. Bride of Christ, remember? She wears her faith lightly: when she’s in the walled garden, it’s to grow cabbages not praise God’s creation, but she still radiates peace, and her vegetable patch radiates it right back at her. In the 90s, Hawes slayed one period drama after another: Wives and Daughters, Our Mutual Friend.…