In the future, a mining colony has been established on Io, the third moon of Jupiter. The new Marshall, William O'Neil (Sean Connery), investigates when there is an increase in grisly suicides, and discovers something rotten in the state of Io: illegal drugs are being offered to workers to increase their productivity but it eventually makes them psychotic. When Sheppard (Peter Boyle), the head of the operation, realizes that O'Neil is out to shut him down, he enlists the aid of two hit men to come to Io and finish off the Marshall, who can expect no help from anyone, including his men. The only exception is the feisty Dr. Lazarus (Frances Sternhagen). This is basically High Noon in outer space. Connery is okay although it might be said that he's just going through the motions, betraying no sense of moral outrage over what's happening to the miners. Sternhagen is simply terrific. The special effects are solid and still hold up thirty years later. Fine score by Jerry Goldsmith.
Verdict: Not exactly original but an interesting variation on a theme. ***.