The Wind Off the Small Isles and The Lost One
Mary Stewart

1968. Perdita West, secretary to a famous author, visits Lanzarote on a research trip and begins to fall in love with the unusual, beautiful little island. When, while snorkelling, a landslide traps Perdita in an underwater cave, her efforts to save herself will reveal what happened to the ill-fated couple who fell in love at this very spot almost a century ago . . .