The case of the backward mule

Chinatown...To baffle the lie-detector clamped on his arm, Terry Clane used the technique of intense concentration that he had learnt in the Orient. But the sight of a little Chinese figure - an old man riding backwards on a mule - sent the lie-detector needle for he had given it once to Cynthia, his former fiancee and a close friend of a man convicted of murder who had escaped.'Either there is something which I have not accurately diagnosed,' said the police examiner, 'or else... you murdered Horace Farnsworth.'That was just the start of a long and spine-chilling game of hide-and-seek played through San Francisco's Chinatown.