Before the Menendez brothers, the Bobbitts or even O.J., Pamela Smart was television's first true-crime fascination; Smart's husband was found murdered and when police began to investigate, they discovered that she was keeping a big secret.

When college student Mackenzie Lueck vanishes from a park in Salt Lake City, her friends are dedicated to finding answers; the search makes national headlines, and the investigation reveals a secret that stuns even her closest friends.