The Ruthless Four (1968)

After years of hard work, old Sam Cooper has finally found a gold mine. Since he cannot take everything he has found with him, he blows up the entrance. To help him exploit his discovery, he calls on his godson Manolo Sanchez. But Manolo is accompanied by "the blond," a strange man who seems to dominate him. Sam has no choice but to accept his company. He persuades his old friend Mason to travel with them as well. Greed and paranoia will eventually completely destroy the small band.