“When in search of a sub-species of the _Papirlionido in the Orinoco region, my party was attacked by the Indians that infest the river. After we had beaten them off, it fell to my lot to attend the wounded. I thus had opportunity to observe the wounds made by their slender spears. The incision under consideration bears a rather striking resemblance to the spear gashes which I saw then. I may add that I brought away my specimens of _Papilionidointact, although we lost most of our provisions.” “No man has been near enough the spot where Serdholm was struck down to stab him,” Haynes said. “Our footprints are plain: so are his. There are no others. What do you make of that?” He was not yet ready to reveal the whole astounding circumstance. “Didn’t I hear somethin’ about that juggler that was cast ashore from the _Milly Esham_ bein’ a knife-thrower?” asked Bruce timidly. “Maybe he spiked Serdholm from the gully.” “Then where’s the knife!” said Haynes. “He’d have to walk out to get it, wouldn’t he?” “You must have overlooked some vestigia,” said the professor quietly. “The foot may have left a very faint mark, but it must have pressed there.” “No; I’m not mistaken. Had you used your eyes, you would have seen.” “How far did Bruce’s footprints go?” asked Colton. The three looked at the coast-guard, who stirred uneasily. “Gentlemen,” said he, “I’m afraid there’s likely to be trouble for me over this.” His harassed eyes roved from one to the other. “Quite likely,” said Haynes. “They may arrest you.” “God knows, I never thought of killing Serd-holm or any other man!” he said earnestly. “But I had a grudge against him, and I wasn’t far away when he was killed. Your evidence will help me, unless-” he swallowed hard. “No; I don’t believe you had any part in it,” said Haynes, answering the unfinished part of the sentence. “I don’t see how you could have unless you can fly.” The man smiled dismally. “And then about those queer tracks——” “Nothing about that now,” interrupted Haynes quickly. “You’d better report to your captain and keep quiet about this thing.” “All right,” said Bruce. “Good-night, gentlemen.” “What’s that about tracks?” asked Colton. “I want you and the professor to come to my room sometime this evening,” said the reporter. “I’ll have a full map drawn out by then, and I want your views. Perhaps you’d better feel my pulse first,” he added, with a slant smile. Colton looked at him hard. “You’re excited, Haynes,” he said. “I haven’t seen you this much worked up. You’ve got something big, haven’t you?” “Just how big I don’t know. But it’s too big for me.” “Well, after you’ve got it off your mind on paper you’ll probably feel better.” “On paper?” “Yes; you’ll report it for your office, won’t you?”