I know nothing about Patricia Highsmith. The acclaimed American author wrote the kind of Sunday-night crime thrillers that put me to sleep. Her best-known creation, the suave psychopath Thomas Ripley, has spawned a number of films that I’ve carefully avoided. But ignorance is an ideal starting point for Switzerland, by Joanna Murray-Smith, a brilliantly nasty comedy that features Highsmith in 1995 when she was past her artistic best.