I am a witch!

From Small Wars, Faraway Places by Michael Burleigh. Page 389.

The Congo had slipped into anarchy. Each day Africans and Europeans seeking rescue mobbed UN posts. The new and highly effective SIS station chief Daphne Park, a dead ringer for Miss Marple even when younger, once had to chase away an intruder in her suburban house by shouting ‘I am a witch! And if you don’t instantly go away your hands and feet will drop fall off.’ This worked. In several provinces communications were impossible. When one official asked for plans of the provincial telephone system, the new chief of communications proudly handed him the telephone directory.