'The Caller' (1987) – Arthur Allan Seidelman.

A seemingly benign, conspicuously polite stranger (Malcolm McDowell) arrives at an isolated house asking the lone female occupant (Madolyn Smith) if he might use the phone, but it later transpires that both of their intentions are altogether twisted indeed! This gripping, enjoyably tense cat & mouse thriller is given a demonstrative boost by Malcolm McDowell's enigmatic performance. Perhaps, better than you might imagine, a smart, compact, robustly acted, well-written Sci-fried drama, Seidelman's inventive, darkly atmospheric thriller features a number of genuinely effective chills, and is strongly recommended. Highlights are McDowall's nuenced acting, Richard Band's score, The Caller's sustained sense of mystery, and a spectacularly bold, wholly unforeseen conclusion. 

“You're a liar!!! what else are you???”