The Tuscan Chalice — Lilian Woodward

When Susan Farnley goes to Italy to join her uncle, she meets Charles Hanson on the night express. Arriving in Tuscany she finds that her uncle has died. Charles takes her to Santa Marbelli surrounded by its vineyards and olive groves - though she is puzzled by some numbers she finds on the back of a photograph inside a locket left to her by her uncle. These, Sue is convinced, are connected with the Monastery of Montabino and Sue and Charles set out to solve the mystery of the Tuscan Chalice.