The roar of a lion is not the kind of music one expects to hear at night in the stillness of the English countryside.

Yet in the neighbourhood of 'Ganges', Sir Benjamin Watson's house, that terrifyingly wild sound is not uncommon. Sir Benjamin is rich enough to indulge his expensive hobby of a private zoo. The first time Ann Sherborne, walking at night to the gates of 'Ganges' on that strange, eventful visit, hears the savage roar, her courage dies and she starts to run.

But that frightening experience is just a prelude to a night charged with terror, when not only fear but death stalks 'Ganges', playing havoc among the guests assembled there ...