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