A tunnel collapses at the Sonderditch gold mine. The collapse was no accident, but part of a plan by a criminal syndicate, which includes the mine owner's son-in-law Manfred Steyner (Bradford Dillman), who wants to destroy the mine and raise the price of gold on the world markets. The mine's General Manager was killed in the tunnel collapse, and the mine owner needs a new replacement. Rod Slater (Roger Moore) is chosen as new General Manager. Slater meets Steyner's wife Terry (Susannah York) and is attracted to her, and he and Terry start a love affair. Slater, unaware of the criminal plan, agrees to carry out the drilling. Steyner knows that Slater is having an affair with his wife, but allows it to continue because it will keep Slater away from the mine, allowing for another mine collapse. Slater and Terry holiday together while disaster strikes at the mine. Slater hears about the disaster, and he and Terry return. What happens next is a suspenseful ending you must see for yourself! This is Roger Moore at his best. An action-thriller of a film! ! (118 minutes - 1974 - Color - 16:9 widescreen)