As Dr. Cairn had declared, the manifestations belonged to one of two varieties. According to the most ancient science in the world, the science by which the Egyptians, and perhaps even earlier peoples, ordered their lives, we share this, our plane of existence, with certain other creatures, often called Elementals. Mercifully, these fearsome entities are invisible to our normal sight, just as the finer tones of music are inaudible to our normal powers of hearing. Victims of delirium tremens, opium smokers, and other debauchees, artificially open that finer, latent power of vision; and the horrors which surround them are not imaginary but are Elementals attracted to the victim by his peculiar excesses. The crawling things, then, which reeked abominably might be Elementals (so Dr. Cairn reasoned) superimposed upon Robert Cairn's consciousness by a directing, malignant intelligence. On the other hand they might be mere glamours--or thought-forms--thrust upon him by the same wizard mind; emanations from an evil, powerful will. His reflections were interrupted by the ringing of the 'phone bell. He took up the receiver. "Hullo!" "That you, sir? All's clear here, now. I'm turning in." "Right. Good-night, Rob. Ring me in the morning." "Good-night, sir." Dr. Cairn refilled his charred briar, and, taking from a drawer in the writing table a thick MS., sat down and began to study the closely-written pages. The paper was in the cramped handwriting of the late Sir Michael Ferrara, his travelling companion through many strange adventures; and the sun had been flooding the library with dimmed golden light for several hours, and a bustle below stairs acclaiming an awakened household, ere the doctor's studies were interrupted. Again, it was the 'phone bell. He rose, switched off the reading-lamp, and lifted the instrument. "That you, Rob?" "Yes, sir. All's well, thank God! Can I breakfast with you?" "Certainly, my boy!" Dr. Cairn glanced at his watch. "Why, upon my soul it's seven o'clock!" CHAPTER VI THE BEETLES Sixteen hours had elapsed and London's clocks were booming eleven that night, when the uncanny drama entered upon its final stage. Once more Dr. Cairn sat alone with Sir Michael's manuscript, but at frequent intervals his glance would stray to the telephone at his elbow. He had given orders to the effect that he was on no account to be disturbed and that his car should be ready at the door from ten o'clock onward. As the sound of the final strokes was dying away the expected summons came. Dr. Cairn's jaw squared and his mouth was very grim, when he recognised his son's voice over the wires. "Well, boy?"