Roger Moore, Susannah York and Ray Milland star in this action drama based on the novel 'Gold Mine' by Wilbur Smith. Rod Slater (Moore) becomes involved in a conspiracy following a tunnel collapse at a South African gold mine owned by Harry Hirschfeld (Milland), in which general manager and veteran miner Frank Lemmer (Norman Coombes) is killed. Hirschfeld's managing director, Manfred Steyner (Bradford Dillman), is plotting with financier Farrell (John Gielgud) to flood and destroy the mine, thus raising the value of gold worldwide, and tricks Slater into excavating the seam of gold beyond the river. Meanwhile, Slater becomes passionately involved with Steyner's wife Terry (York), unaware that the scheme hatched by her husband will result in his death.