A series of gruesome accidents plague a small American farming community in the summer of 1935, encircling two identical twin brothers and their family.
| Writing | Tom Tryon | Screenplay |
| Directing | Robert Mulligan | Director |
| Editing | Folmar Blangsted | Editor |
| Production | Robert Mulligan | Producer |
| Editing | O. Nicholas Brown | Editor |
| Sound | Jerry Goldsmith | Original Music Composer |
| Camera | Robert Surtees | Director of Photography |
| Writing | Tom Tryon | Novel |
| Production | Tom Tryon | Executive Producer |
| Art | Albert Brenner | Production Design |
| Production | Don Kranze | Associate Producer |
| Production | Alixe Gordin | Casting |
| Production | William J. Kenney | Casting |
| Art | Albert Brenner | Art Direction |
| Art | Jack Martin Smith | Art Direction |
| Art | Ruby R. Levitt | Set Decoration |
| Art | Walter M. Scott | Set Decoration |
| Costume & Make-Up | Joe DiBella | Makeup Artist |
| Costume & Make-Up | Dorothy White | Hairstylist |
| Directing | Bert Gold | Assistant Director |
| Directing | Don Kranze | Assistant Director |
| Directing | Mark Sandrich Jr. | Assistant Director |
| Directing | John Barnwell | Second Assistant Director |
| Art | Barry Bedig | Property Master |
| Art | Earl W. Huntoon, Jr. | Leadman |
| Crew | Clarence Fay Konkel | Carpenter |
| Art | Bill Parks | Construction Coordinator |
| Art | Ward Preston | Assistant Art Director |
| Sound | Don J. Bassman | Sound |
| Sound | Jack Solomon | Sound |
| Sound | Al Yaylian | Boom Operator |
| Camera | Richard Barth | First Assistant Camera |
| Camera | James R. Connell | Camera Operator |
| Camera | Bud Gray | Still Photographer |
| Lighting | Earl Kennedy | Gaffer |
| Camera | Dan Lambert | Key Grip |
| Production | Jim Riggs | Local Casting |
| Production | Joanne Riggs | Local Casting |
| Costume & Make-Up | Joanne Haas | Costumer |
| Costume & Make-Up | Thomas Welsh | Costumer |
| Sound | Arthur Morton | Orchestrator |
| Sound | Alexander Courage | Music |
| Sound | Alexander Courage | Music Arranger |
| Sound | Jerry Goldsmith | Conductor |
| Sound | Emil Richards | Musician |
| Directing | Ray Quiroz | Script Supervisor |
| Crew | Aram Betkijian | Transportation Captain |
| Production | Estelle Schaffe | Production Secretary |
