The instant effect of this last interruption was to divert the angry feelings of the brothers from their former course and combine them against Payner. He was the cause of all the trouble; without him and his outrageous interference, the Moons would never have had a suspicion. He should be punished; his room should be ripped up, and ripped up thoroughly. The discussion of a plan reinfused in the twins the old spirit of unity and harmony. But Payner was not so easily caught as the heedless Moons. The twins obtained a schedule of his recitations and laboratory hours, which they agreed afforded the only safe occasions to work. At some of these hours they were themselves employed; at others, when they tried his door, it proved to be securely locked. Once, indeed, during a laboratory period, they found the door ajar, and pushing it open went boldly in to make the most of their opportunity. Donald was in the van, his eyes eagerly sweeping the walls of the room in search of material suited to his purpose. Duncan, close behind him, glanced over the table, and perceived a bristly head of hair just appearing above the table edge. Before they could draw back, the bristling scalp rose higher, and two savage little eyes looked straight into Donald's face. It was Payner himself, who had been sent back from the laboratory for the note-book which he had neglected to bring with him. Donald sprang back speechless. Duncan came forward pulling out his watch. "Well?" said Payner. He was not given to long speeches, but he could put much vigor into short ones. "Have you the right time about you?" Duncan asked with a certain degree of composure. "We saw your door open and thought we'd come in." "So I see," remarked Payner. "He"--jerking his head toward Donald--"seemed rather surprised to find me in." "It's enough to surprise any one to have a fellow pop up like a jack-in-the-box from behind a table!" "Jack-in-the-box!" repeated Payner, angrily. "Well, anything you like," said Duncan, smiling. "Did you say you had the right time?" "No, I haven't; my time is always wrong." "Thanks," returned Duncan; "then we won't trouble you any longer. Come on, Don, let's try Owen." The brothers turned to go. "The next time you come you'd better knock first," shouted Payner. "It'll save your nerves!" "We'll try to remember," said Donald, who had regained his composure. It was his only part in the interview. The brothers crept back to their room and there chuckled mightily over their escape. Payner listened to see whether they really did visit Owen, and then locking his door carefully, walked over to the laboratory, far more disturbed by the problem of the Pecks' presence in his room than by any difficulty which an experiment in physics might offer. And Payner did not shine in physics.