“Owing to its structure,” said the professor, “the pteranodon could not rise rapidly from the ground in flight. It either sought an acclivity from which to launch itself, or ran swiftly along the ground, gathering impetus for a leap into the air with outspread wings. Similarly, in alighting, it probably ran along on its hind feet before dropping to its small fore feet. Now, conceive the pteranodon to be on the cliff’s edge, about to start upon its evening flight. Below it appears a man. Its ferocious nature is aroused at the sight of this unknown being. Down it swoops, skims swiftly with pattering feet toward him, impales him on its dreadful beak, then returns to climb the cliff and again launch itself for flight.” All this time Haynes had been holding one of the smaller rocks in his hand. Now he flung it toward the gully and turned away, saying vehemently: “If the shore was covered with footprints, I wouldn’t believe it! It’s too—” He never finished that sentence. From out of the darkness there came a hoarse cry. Heavy wings beat the air with swift strokes. In that instant panic fell upon them. Haynes ran for the shelter of the cliff, and after him came the Coltons. Johnston dropped on hands and knees and scurried like a crab for cover. Only the professor stood his ground; but it was with a tremulous voice that he called to his companions: “That was a common marsh or short-eared owl that rose. The _Asio accipitrinus_ is not rare hereabouts, nor is it dangerous to mankind. There is nothing further to do to-night, and I believe that we are in some peril remaining here, as the pteranodon appears to be nocturnal.” The others returned to him ashamed. But all the way home they walked under an obsession of terror hovering in the blackness above. It was a night of restless and troubled sleep at Third House. For when the incredible takes the form of undeniable reason, and demands credence, the brain of man gropes fitfully along dim avenues of conjecture. Helga’s premonition of impending disaster lay heavy upon the household. CHAPTER THIRTEEN THE NEW EVIDENCE THE morning of September 21 impended in sullen splendour from a bank of cloud. As the sudden sun struggled into the open it brought a brisk blow from the southwest, dispelling a heavy mist. The last of the fog was being scoured from the earth’s face when Dick Colton was awakened from an unrefreshing sleep by a quick step passing down the hall. Jumping out of bed, he threw open the door and faced Haynes. “Don’t wake the others,” said the reporter in a low voice. “Where are you off to?” inquired Colton. “To the beach. I’ve got a notion that I can settle this Serdholm question here and now.” “Wait fifteen minutes and I’ll go with you.” “If you don’t mind, Colton, I’d rather you wouldn’t. I want to go over the ground alone, first. But if I’m not back for breakfast, meet me there and I’ll probably have something to tell you.”