"How do we know?  We saw a man about the right age in a hospital bed.  We have Berquist's word for it - and Berquist got his start in politics issuing denials; his word means nothing.  We saw a total stranger, supposed to be a psychiatrist... and when I tried to find out where he had studied psychiatry I got euchred out.  How do we know?  Mr. Cavendish, did you see or hear anything that convinced you that this bloke was the Man from Mars?"