Saint Agatha Healed in Prison by Saint Peter

For a long time scholars argued over whether this canvas was by Lanfranco at all. A second version hangs in the Galleria Nazionale in Parma, and many took the Roman picture for a copy, not least because it was hard to read under a heavy yellowish cast. A restoration in 2011 changed that. The yellow turned out to be oxidised varnish and a resin layer tinted with bitumen, and once they came off the flesh tones turned pearly again. The cleaning also showed numerous changes of mind. The angel's hand with the ointment had first been placed higher, and Peter's nose and the fingers of his healing hand were shifted. The museum takes these as proof that the painting is no copy. Small holes at even intervals along the edges suggest Lanfranco nailed a squared drawing to the canvas while he worked.

The story is that of Agatha, a young Sicilian noblewoman martyred under the emperor Decius. Her breasts had been cut off, and in the night Saint Peter and an angel came to her cell to heal her. Lanfranco painted it between about 1612 and 1615, the figures surfacing from the dark in the light from the cell window, something he owed to Caravaggio's followers in Rome as much as to Correggio, the great painter of his native Parma. Compared with the Parma version, the three figures stand close together. Here the angel holds the bowl, and Peter's hand stays raised in the air, as if he hesitated before touching her wounds.