Two teenage girl decide to have an evening of fun by making prank calls with the following "I saw what you did, and I know who you are.". However as go through the night they call a man who has recently killed his wife. The man takes them seriously and attempts to hunt them down to silence them preeminently.

Directed by William Castle.

The film was released on Blu-Ray by Shout/Scream Factory in 2016.

In 1988 the film was remade as a TV movie.