“A policeman?” he said, laughing vaguely. “Whatever made you think of a policeman in connection with me?”
“The process was simple enough,” answered the Professor patiently. “I thought you looked like a policeman. I think so now.”
“Did I take a policeman’s hat by mistake out of the restaurant?” asked Syme, smiling wildly. “Have I by any chance got a number stuck on to me somewhere? Have my boots got that watchful look? Why must I be a policeman? Do, do let me be a postman.”
The old Professor shook his head with a gravity that gave no hope, but Syme ran on with a feverish irony.
“But perhaps I misunderstood the delicacies of your German philosophy. Perhaps policeman is a relative term. In an evolutionary sense, sir, the ape fades so gradually into the policeman, that I myself can never detect the shade. The monkey is only the policeman that may be. Perhaps a maiden lady on Clapham Common is only the policeman that might have been. I don’t mind being the policeman that might have been. I don’t mind being anything in German thought.”
“Are you in the police service?” said the old man, ignoring all Syme’s improvised and desperate raillery. “Are you a detective?”
Syme’s heart turned to stone, but his face never changed.
“Your suggestion is ridiculous,” he began. “Why on earth—”
The old man struck his palsied hand passionately on the rickety table, nearly breaking it.
“Did you hear me ask a plain question, you pattering spy?” he shrieked in a high, crazy voice. “Are you, or are you not, a police detective?”
“No!” answered Syme, like a man standing on the hangman’s drop.