An honest marshal in a corrupt mining colony on Io, Jupiter's sunless third moon, is determined to confront a violent drug ring even though it may cost him his life. After his wife angrily deserts him, he waits alone for the arrival of killers hired by the company to eliminate him.
| Directing | Peter Hyams | Director |
| Writing | Peter Hyams | Screenplay |
| Sound | Jerry Goldsmith | Original Music Composer |
| Camera | Stephen Goldblatt | Director of Photography |
| Editing | Stuart Baird | Editor |
| Production | Richard A. Roth | Producer |
| Production | Mary Selway | Casting |
| Costume & Make-Up | John Mollo | Costume Design |
| Art | Stuart Rose | Set Decoration |
| Art | Philip Harrison | Production Design |
| Art | Malcolm Middleton | Art Direction |
| Crew | Danny Skundric | Property Master |
| Camera | Freddie Cooper | Camera Operator |
| Camera | Bob Kindred | Camera Operator |
| Camera | George Whitear | Still Photographer |
| Costume & Make-Up | Tiny Nicholls | Costume Supervisor |
| Sound | George Korngold | Music Editor |
| Sound | Leonard A. Engel | Music Editor |
| Crew | Anthony Van Laast | Choreographer |
| Sound | Clyde McKinney | Dolby Consultant |
| Sound | Gordon Davidson | Supervising Sound Editor |
| Costume & Make-Up | Peter Robb-King | Makeup Artist |
| Sound | Robin Gregory | Sound Mixer |
| Costume & Make-Up | Colin Jamison | Hairdresser |
| Sound | Jay Engel | ADR Editor |
| Sound | Scott Burrow | Assistant Sound Editor |
| Sound | Jeffrey Landgren | Assistant Sound Editor |
| Sound | Terry Sharratt | Boom Operator |
| Sound | Neil Burrow | Sound Editor |
| Sound | David M. Horton | Sound Editor |
| Sound | Richard Oswald | Sound Editor |
| Sound | Chester Slomka | Sound Editor |
| Lighting | John May | Gaffer |
| Editing | Russ Woolnough | First Assistant Editor |
| Directing | June Randall | Continuity |
| Production | Fred Harding | Production Accountant |
| Crew | Lynda Levy | Unit Publicist |
| Art | Peter Donen | Title Designer |
| Crew | John Stears | Special Effects |
| Art | Albert Blackshaw | Construction Manager |
| Production | Denis Johnson | Production Manager |
