Una raza extraterrestre trata de invadir La Tierra apoderándose del cuerpo de varios seres humanos. El Dr. Scott Dyden tratará de impedirlo.
 | Tom Mason | Dr. Scott Dryden |
| Eric Braeden | Leonard Nero |
| Melinda O. Fee | Gwendolyn O'Brien |
| Fawne Harriman | Joyce Cummings |
| Matthew Labyorteaux | Timmy Garner |
| Ron Masak | Harve Nelson |
| Caroline McWilliams | Sue Garner |
| John Milford | Eldon Gates |
| Max Gail | Russ Garner |
 | Ed Harris | Chuck Polcheck |
| Hank Brandt | Teniente Coronel John Sebastian |
| Laurence Haddon | Bert Fowler |
| Gerald McRaney | Patrolman Ashley |
| Curtis Credel | Frank Foley |
| Richard Lockmiller | Patrullero |
