Greenwell is a master of precision: everyday intimacy is so well wrought that it can feel unbearable to read, as if he cuts too close to the skin. A book’s greatest achievement is often seen as the moment when the reader recognises a part of themselves that they hadn’t yet verbalised. Greenwell’s writing achieves this effortlessly, but in Cleanness he gives something more. In the warmth that rises through his prose there is a poignant optimism. It leaves the reader with the hope that it might spread.