In the fictional country "Bandrika" a motley group of travellers eager to return to England is delayed by an avalanche that has blocked the railway tracks. At night, a singer plays a tune al fresco that catches the attention of Miss Froy, an elderly lady. The singer is suddenly silenced—apparently murdered. Among the train's passengers are Gilbert, a musicologist who has been studying the folk songs of the region, Iris, a young woman of independent means.
