“Well!” gasped my friend, amazed. “By Gad! I never expected that!”

“Neither did I,” was my breathless reply. “But the reason of poor Guy’s death is now vividly apparent. He was bitten by that arachnid, which Shaw, in all probability, purposely left in his young friend’s library, prior to returning home on that fatal night. I think I realise the truth!” I cried. “This particular species of lycosa tarantula is, I have read, found in the primeval forests of Peru, and will only attack human beings when they are motionless or asleep. Its bite is most deadly. It causes stupor, followed by coma or paralysis, and the victim rapidly dies. Yet if the mark of its bite be concealed and unsuspected, as it may easily be in the hair, then the symptoms are identical with those of inflammation of the brain—the disease which from poor Guy is supposed to have died!”

“Then you suspect Shaw of having kept the horrible thing as a pet—eh!” he gasped, staring at me amazed.

“Both as a pet and as an instrument of murder,” I replied. “The thing being nocturnal in its habits would, if introduced into a room, remain carefully hidden all day, and only attack the victim at night while he is sleeping. I had a narrow escape while motoring in France with Shaw,”—and then, in a few words, I described my own experience, and also Asta’s previous sight of what had appeared to both of us as a weird, uncanny hand.

“Then this scoundrel Shaw evidently intended that you should die!” he exclaimed. “By Jove! old chap, you have had a narrow escape!”

“Yes. He must have carried his dangerous pet in secret in a box, I suppose. And must have taken it away with him when he fled from Aix.”

Then, suddenly recollecting that curious whistle of his, I realised how Shaw had used it in order to recall the great spider.

“Put out the light, Cardew,” I said. “Have your torch ready. I have an idea.”

“But—” he hesitated, in apprehension.

“Have no fear. We want to see the hideous thing again—and to kill it,” I said.