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