"I—er—I think we owe you an apology," he said. "My suspicions were unfounded. However, I did my duty to my country by having you examined. You must admit your conduct was suspicious—highly suspicious, sir!"

Sarakoff replaced the tube and locked the bag. Lord Alberan marched to the door and held it open.

"We need not detain you, sir," said the detective. The policeman squared his shoulders and hitched up his belt. The station official looked nervous.

Dr. Sarakoff, with a gesture of indifference, picked up the bag and, taking me by the arm, passed out on to the brilliantly-lit platform. "Pyocyaneus," he muttered in my ear; "pyocyaneus, indeed! Confound the fellow. He might have got me into no end of trouble if he had known the truth, Harden."

"But what is it?" I asked. "What have you got in the bag?"

He stopped under a sizzling arc-lamp outside the station.

"The bag," he said touching the worn leather lovingly, "contains six tubes of the Sarakoff-Harden bacillus. Yes, I have added your name to it. I will make your name immortal—by coupling it with mine."

"But what is the Sarakoff-Harden bacillus?" I cried.

He struck an attitude under the viperish glare of the lamp and smiled. He certainly did look like an anarchist at the moment. He loomed over me, huge, satanic, inscrutable.

A thrill, almost of fear, passed over me. I glanced round in some apprehension. Under an archway near by I saw Lord Alberan looking fixedly at us. The expression of suspicion had returned to his face.