Kathy Austin's hopes of taking a genuine holiday in Scotland seem dashed as more strange phenomena continue to plague her. On top of her family home having mysteriously burned down, a nightly encounter with an almost inhuman-looking individual briefly sends her to the hospital, where she is soon joined by a catatonic young woman found naked on a nearby beach. With this accumulation of bizarre events coinciding with the presence of known Soviet spies, MI6 finally decides to send her some backup ...