We saw this in person in Edinburgh; hard to think of a picture that speaks so powerfully and bracingly for itself (but yes i will go on anyway). All colour – bar the heavy, slate grey – is drained away, leaving only touches of blue and the red of blood. The children’s limp bodies are horrifyingly piled one on top of the other, a brutalised reminder of Duchamp’s Nude (1912), another painting that sought to capture movement rather than a moment. Look how the hands are so tender and feeling, especially as counterpoint to the weight of what they hold. And the heaviest artistic influence is the renaissance Pietà (hence the blue, perhaps): the mother cradling her child – what Michelangelo called “the heart’s image” – but all we see of the mother here is those hands, her very self lost in the all-consuming senselessness of grief.