The fourth volume in The Hawk and Dove series centred around a fictional Benedictine monastery in Yorkshire.

The Hardest Thing to Do starts one year after The Long Fall. The monastery of St Alcuin's is settling down and adjusting to the new abbot who has been chosen to take the place of Father Peregrine. Then a deeply detested enemy, Prior William, arrives seeking refuge. Reluctantly taking in the man who so ill-treated their much-loved former leader, the upended community must address old fears and bitterness while warily seeking reconciliation. But will William the refugee spread poison, or receive healing? In her fourth book in the series, Penelope Wilcock wrestles with the difficulties of forgiveness and the cautions of building trust. What is truly the hardest thing to do?