A guesthouse receives written alibis from every person booked for the same weekend, although no crime has occurred. Its owner and a local bus driver discover the letters describe an event scheduled for Sunday, leaving them two days to decide whether they are witnesses or props.
In 1931, an alpine funicular arrives with one dead passenger and no tracks leading to the upper station. A ticket inspector must solve a journey someone has counted from the wrong end.
In 1924, a portrait painter recognizes a dinner guest whose death she helped document. When another guest is killed, she must separate an invented identity from a very real history of blackmail.