“An opinion based upon your actions towards me!” I exclaimed hotly.

“My dear Holford,” he said, “now let us speak quite frankly, as man to man.” And he bent towards me in an eager attitude. “I put it to you whether, in the circumstances—not overlooking the fact that Scotland Yard has refused you assistance—to forget what you saw that night upstairs in the laboratory, to place it aside as though you never witnessed it, is not the best plan?”

“Ah, you wish still to hush up the tragedy!” I cried. “The reason is, of course, quite obvious.”

“You misinterpret my words. I wish to avoid bringing scandal upon innocent folk,” Kirk replied quickly. “You once gave me a pledge of secrecy, and you broke it. Will you give me another?”

“And if I gave it,” I asked, not without some hesitation, “would these precious friends of yours give me back my wife?”

“I cannot answer for others. Personally, I will do all I can to assist you,” was his somewhat evasive reply.

“Why do you wish to extract this promise from me?” I demanded dubiously.

“Because—well, because you must give it. You must remain silent, Holford. It is imperative!”

“You really ask too much of me,” I laughed sarcastically. “I know the ghastly truth. You showed it to me of your own accord—you yourself drew me into this dark, mysterious affair, and now you coolly demand my silence, because you are, I suppose, interested in the money realised by the sale of Professor Greer’s secret.”

“Ethelwynn Greer makes the same demand as myself,” he said calmly. “Surely you don’t believe that the girl has participated in any shamefully obtained profits?”