Danny Boy - S1.E6

Rupert and Amy are in Manchester awaiting the arrival of a Hollywood producer who wants to make a film of one of Rupert's books. At dinner the night before the producer's arrival, Rupert speculates about a fellow diner who is demanding that the violinist play Danny Boy. The diner is American and Rupert thinks he looks like a Godfather type. The next morning, when they are meeting the producer at the airport, Rupert and Amy witness the arrival of an American singer, Carole Fortune, and notice that she is being watched by the 'Godfather' from the previous evening. Rupert is worried that the Godfather is going to kidnap the singer so he leaves Amy to deal with the Hollywood producer while he investigates.