The superintendent caught up his hat and strode away, the personification of mental alertness and bodily vigour.
No sooner had the door closed behind him than Thorndyke's stolid calm changed instantaneously into feverish energy. Darting to the electric bell that rang into the laboratories above, he pressed the button while he gave me my directions.
"Have a look at that blood-stain, Jervis, while I am finishing with Belfield. Don't wet it; scrape it into a drop of warm normal saline solution."
I hastened to reach down the microscope and set out on the table the necessary apparatus and reagents, and, as I was thus occupied, a latch-key turned in the outer door and our invaluable helpmate, Polton, entered the room in his habitual silent, unobtrusive fashion.
"Let me have the finger-print apparatus, please, Polton," said Thorndyke; "and have the copying camera ready by nine o'clock. I am expecting Mr. Miller with some documents."
As his laboratory assistant departed, Thorndyke rapped at the office door.
"It's all clear, Belfield," he called; "you can come out."
The key turned and the prisoner emerged, looking ludicrously woebegone in his ridiculous wig and beard.
"I am going to take your finger-prints, to compare
