Pestilence, resulting from German experiments, during the war, in mycelian cultures, appears first in Russia then in England and it is up to biologists Hearn and Durford to analyze its origins and possible prevention. Kirk, of R.M. Foreign Office, heads up the search for researcher, German Ross Steinberg, moves in unorthodox fashion to learn her whereabouts, while Durford's wife follows her own logic and heads for Rosa's hiding-place. Danger -- from the fungold mutations and Rosa's fanaticism -- for the Durfords and the world- is averted in a last minute finish. The horrors and menaces department.