Guest Stars Peter Thompson as Primord Christopher Benjamin as Sir Keith Gold Roy Scammell as RSF Sentry Walter Henry as Primord Philip Ryan as Primord Sheila Dunn as Dr. Petra Williams Sheila Dunn as Petra Williams Keith James as Patterson Walter Randall as Harry Slocum Dave Carter as Primord Pat Gorman as Primord Derek Ware as Private Wyatt David Simeon as Private Latimer Derek Newark as Greg Sutton Olaf Pooley as Professor Stahlman Olaf Pooley as Director Stahlman Ian Fairbairn as Bromley
