Epitaph for a Spy — Eric Ambler

When Josef Vadassy arrives at the Hotel de la Reserve at the end of his Riviera holiday, he is simply looking forward to a few more days of relaxation before returning to Paris. But in St. Gatien, on the eve of World War II, everyone is suspectâ€"the American brother and sister, the expatriate Brits, and the German gentleman traveling under at least one assumed name. When the film he drops off at the chemist reveals photographs he has not taken, Vadassy finds himself the object of intense suspicion. The result is anything but the rest he had been hoping for.