 Preparations on the day at the home of Lord Rustonbury are going well until Signor Roscari, due to sing the part of Scarpia, suddenly falls strangely ill. Lady Rustonbury remembers that a nearby neighbour is Edouard Bréon, the retired French baritone and she drives off to ask him to step in at the last moment.He agrees and returns.In the hall of the castle he reminisces over past performances of Tosca that he has heard, stating that the best one was over twenty years before by a young girl called Bianca Capelli.