Guest Stars Frederick Jaeger as Commander Fletcher Paul Eddington as Strand Dennis Waterman as Frank Gosling Ronald Radd as Leonard Gosling Charles Farrell as Harry Christopher Benjamin as Dr. Eric Blyth Ray Mort as Ron Murray Stephanie Turner as Jean Gosling Lynn Dalby as Carole Murray Barrie Cookson as Lemner Eric Mason as Steve Edwin Apps as Major Philip Erskine Jonathan Elsom as Koniev Julie Anderson as Teresa