“And when did he retire from his profession?”

“About fifteen years ago.”

“And he resolved to say good-bye to the Bar and devote himself entirely to politics?”

Sheila nodded. “That is quite true. He had a very firm opinion that a man could not serve two masters.”

“Was he on the Chancery or the Common Law side?” was Smeaton’s next question.

“On the Common Law,” replied Sheila. “But why do you ask that question?”

“You shall know in good time. Miss Monkton. Well, we may take it, then, that this vindictive letter was written more than fifteen years ago.”

“While he was still at the Bar,” interrupted Wingate, who was beginning to realise the point of the detective’s reasoning. “You are assuming that this venomous epistle did not come from a political enemy.”

“It is an assumption for which I have reasonable grounds,” was Smeaton’s answer. “There has been no bitterness in party politics ever since Mr Monkton became a conspicuous figure in the House. And we know that, while he was most popular with his own side, he was respected and liked by his political opponents.”

“Is it too much to ask you to give us the benefit of any theory you have formed, Mr Smeaton?” suggested Sheila, in her pretty, gracious way.