ce for a
moment, only broken by hurrying footsteps on the platform without. Then
Lord Alberan stepped cautiously forward.

He saw the worn canvas lining of the bag. He took a step nearer and saw
a wooden rack, fitted in the interior, containing six glass tubes whose
mouths were stopped with plugs of cotton wool.

"You see, there is nothing important there," said Sarakoff with a smile.
"These objects are of purely scientific interest." He took out one of
the tubes and held it up to the light. It was half full of a
semi-transparent jelly-like mass, faintly blue in colour. The detective,
the policeman and the station official clustered round, their faces
turned up to the light and their eyes fixed on the tube. The Russian
looked at them narrowly, and reading nothing but dull wonderment in
their expressions, began to speak again.

"Yes--the Bacillus Pyocyaneus," he said, with a faint mocking smile and
a side glance at me. "It is occasionally met with in man and is easily
detected by the blue bye-product it gives off while growing." He twisted
the tube slowly round. "It is quite an interesting culture," he
continued idly. "Do you observe the uniform distribution of the growth
and the absence of any sign of liquefaction in the medium?"

Lord Alberan cleared his throat.

"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 un