The good, the bad and the bloody reveal the final troubled, violent genius of Caravaggio

THERE'S a good girl and a bad girl in the National Gallery's show billed as The Last Caravaggio.

- Melanie McDonagh

On the one wall, there's Salome, who is just taking possession of the head of John the Baptist from the headsman after her Dance of the Seven Veils; her face is turned aside from her prize, and no wonder. And on the wall facing the viewer, there's poor St Ursula looking wonderingly down at the wound in her breast from the arrow of the pagan Hun, who has just shot her in pique and at alarmingly close range after she rejected him.

This being Caravaggio, what we've got is theatre in light and dark: the luminous figure of St Ursula - whose deathly pallor contrasts with her blood red cloak-is the first thing that strikes viewers as they enter.