Sand Trap (1998)

After falling victim to a burglar Nelson a wealthy businessman takes a trip to the desert with his wife Margo and lawyerfriend Jack The trip takes an unexpected turn when Jack helps Nelson over a cliff Jack and Margo return to the site with the sheriff only to discover Nelsons body is missing indicating he is still alive As Nelson struggles to survive against madness and the elements two separate searches for him are conductedone by an increasingly suspicious sheriff and the other by the treacherous Margo and Jack