While exploring in some caves, two boys go missing. Ridge and Hardcastle investigate, but when they visit a local building they are strongly warned off by an army unit, which has taken over the entire area, killing any intruding animals and showing hostility to any human intruders. Doomwatch soon discover that during the Second World War, the mansion was used as a base for the development of bacterial warfare, and that the chemical weapons which were stored there have now somehow leaked into the local water supply.
Did You Know?
13.6 million viewers watched the broadcast of this edition; this was the most-watched episode of the whole Doomwatch
(1970) run. See more