“Do not excite yourself,” said Poirot placidly. “Do not play the farce of the honest, injured man. You know all there is to know about the blackmail, is it not so?”
“Sir, I—I’ve never—never been——”
“Insulted,” suggested Poirot, “in such a way before. Then why, my excellent Parker, were you so anxious to overhear the conversation in Mr. Ackroyd’s study the other evening, after you had caught the word blackmail?”
“I wasn’t—I——”
“Who was your last master?” rapped out Poirot suddenly.
“My last master?”
“Yes, the master you were with before you came to Mr. Ackroyd.”
“A Major Ellerby, sir——”
Poirot took the words out of his mouth.
“Just so, Major Ellerby. Major Ellerby was addicted to drugs, was he not? You traveled about with him. When he was in Bermuda there was some trouble—a man was killed. Major Ellerby was partly responsible. It was hushed up. But you knew about it. How much did Major Ellerby pay you to keep your mouth shut?”