The hunter rubbed his rather prominent nasal organ and was silenced. Jack and Mark had turned more eagerly to the professor as the latter began to speak: "Yes, Dr. Todd is my good friend. He turns to me for help quite properly; who else should he turn to?" "But, Professor!" ejaculated Mark, warmly. "Are you to be driven off to Alaska at your age to hunt for this herb--which is perhaps only the hallucination of a madman?" "Mark's hit the nail on the head, Professor!" declared Jack. "I believe this Todd must certainly be 'touched' in his upper story." "Am _I_ touched, as you call it, Jack?" demanded Professor Henderson, in some indignation. "But you don't believe Todd is on the trail of any great discovery?" cried Mark. "Why not? Mind may yield to herbal treatment. Todd is an advanced botanical adherent. He believes almost anything can be accomplished by herbs. And he says he has successfully treated one case." "One swallow doesn't make a summer," remarked Mark, doubtfully. "But it is enough that he wants us to find the herb," said the professor, more vigorously. "'Us'!" repeated Jack. "And he will pay us any reasonable price for our work," added their mentor. "He really means to go!" cried Mark. "I certainly do. I think you and Jack will accompany me," said the professor, quietly. "I know that Washington will, and of course Andy will not be left behind." "Not if there'll be a chance at big game," declared the hunter. "I'm with you, Professor Henderson." "Yo' suah can't git erlong widout me, I s'pose?" queried the darkey, in some uncertainty. "I'se mighty busy right yere jes' now." "And you'll be busy if we go to Alaska, Wash!" cried Jack. "Hurrah! I am willing to start to-morrow, Professor." "And you, Mark?" queried the old gentleman of his other adopted son. "How will we go, sir? We shall be until fall traveling to the Arctic Circle by any usual means." "True," said the professor. "And haste is imperative. I cannot spend much time in this matter. We must take unusual means of getting to the Endicott Range." "What do you mean?" asked the boys in chorus. "Your _Snowbird_ is ready for flight. It can be provisioned and will take us all quicker than by any other means. Therefore in the _Snowbird_ we will make the journey." CHAPTER III THE FLIGHT OF THE SNOWBIRD Jack Darrow and Mark Sampson were glad enough to be of the party aiming to reach northern Alaska and the Endicott Range, if Professor Henderson really intended going to find the strange herb for which Dr. Todd was willing to pay so generously. Of discussion, pro and con, there was much. Indeed, they sat up until after midnight after the reading of Dr. Todd's letter, talking over the contemplated journey, and gradually the details of the trip, including all preparations for it, were worked out.