Crossing the sun-scorched desert to Mexico, six misfit convicts find a gold medallion covered with unknown symbols. An Apache holy man tells them of lost Spanish gold, torn from the heart of the Guachapa Mountains centuries ago and guarded by seven Jesuit priests who died and were mummified to protect the Tumacacori treasure forever. The six convicts must do battle with the seven mummies in order to extract the rest of the mysterious treasure.