The twin paintings were discovered by the relations of a deceased retired librarian, still hanging discreetly where she left them - behind her spare room door in a modest house in Oxford. They had originally formed the altarpiece of the Chapel of the Monastery of San Marco, Florence. Jean Preston was her name; she lived a simple life in retirement and had acquired the works for very little in a box of curios, back when she worked in San Francisco in the 1960s. The auctioneer, Guy Schwinge, who is getting something of a name for surprise discoveries of undoubted authenticity, will ensure that the paintings are sold imminently. They are unlikely to rejoin the main panel of the Madonna and Child in Fra Angelico's Florence work. There are six other 'saints', all in other collections and dispersed worldwide. It would be great if the two saints now discovered could be reinstalled either side of the Madonna in the Piazza San Marco. But how?