Watch Lake Mungo for Free: How to Stream the Movie Online at 123Movies. . After 16-year-old Alice Palmer drowns at a local dam, her family experiences a series of strange, inexplicable events centered in and around their home. Unsettled, the Palmers seek the help of a psychic and parapsychologist, who discovers that Alice led a secret, double life. At Lake Mungo, Alice's secret past emerges.