Watch El gran marciano for Free: How to Stream the Movie Online at 123Movies. . The group of fourteen contestants from the television program "Big Brother" becomes a privileged witness to the most extraordinary event that the austere region of Extremadura has experienced in its history. Charred remains of what doesn't look like a man-made ship float in a hotel pool. And at night, a thunderous noise and a light that invades everything prevents them from sleeping.