As Far as You Can Go — Lesley Glaister

When Cassie sees a job advertised for a couple to run a remote Australian farm, she thinks it will be the perfect escape for her and Graham. But trapped under the baking sun of the outback, paranoia sets in. There's no radio and they send but never receive any letters. Their enigmatic and unusually forgiving boss Larry and his wife Mara have secrets, sedatives, and some very odd habits: a result of their isolated lifestyle or something more sinister? And there's always the sensation, in the stark brush of the red desert, that eyes are watching them