I leaped into the cab.

Within five seconds from the time that I slammed the door and dropped back panting upon the cushions, we were speeding westward toward the house of the famous pathologist, thereby throwing the police hopelessly off the track.

Faintly to my ears came the purr of a police whistle. The taxi-man evidently did not hear the significant sound. Merciful Providence had rung down the curtain; for to-night my role in the yellow drama was finished.

[ [!-- H2 anchor --] ]

CHAPTER XXI. CRAGMIRE TOWER

Less than two hours later, Inspector Weymouth and a party of men from Scotland Yard raided the house in Museum Street. They found the stock of J. Salaman practically intact, and, in the strangely appointed rooms above, every evidence of a hasty outgoing. But of the instruments, drugs and other laboratory paraphernalia not one item remained. I would gladly have given my income for a year, to have gained possession of the books, alone; for, beyond all shadow of doubt, I knew them to contain formula calculated to revolutionize the science of medicine.

Exhausted, physically and mentally, and with my mind a whispering-gallery of conjectures (it were needless for me to mention whom respecting) I turned in, gratefully, having patched up the slight wound in my calf.

I seemed scarcely to have closed my eyes, when Nayland Smith was shaking me into wakefulness.

“You are probably tired out,” he said; “but your crazy expedition of last night entitles you to no sympathy. Read this; there is a train in an hour. We will reserve a compartment and you can resume your interrupted slumbers in a corner seat.”

As I struggled upright in bed, rubbing my eyes sleepily, Smith handed me the Daily Telegraph, pointing to the following paragraph upon the literary page: