Up they went; Hugo nimbly and Humphrey clumsily and slowly, as became his years and experience, as William Lorimer would have said if he had seen him. Barely had they reached complete cover, and the rustling they made had just ceased, when the tramp of two approaching horses was heard. The sky was now overcast with clouds in spite of the prognostications of the owls, and the rain began to descend heavily, so that the two riders sought refuge beneath the tree. Hugo and Humphrey looked at each other and then down upon the horsemen, who were the two spies, Walter Skinner and Richard Wood. "I had thought to have come up with them ere this," said Walter Skinner. "They had not more than half an hour the start of me." "Have no fear," replied Richard Wood, who was a tall and determined-looking man. "They have most like gone on to Selby on the north side of the river. We shall catch them there." [Illustration: Humphrey and Hugo in the Oak Tree] "Thou saidst there is no one to watch the castle?" inquired Walter Skinner. "Ay, I said it," returned Richard Wood. "Why, who should there be when Sir Thomas hath taken the other two and gone off to get a troop together against Robert Sadler's return? There be thirty men-at-arms within the castle, and all will fight to the death if need be, and none more fiercely than William Lorimer. So saith Robert Sadler. He giveth not so brave an account of the warder and the grooms at the drawbridge, for, saith he, 'The warder is old and slow, and the grooms stupid.' It was well we fell in with Robert Sadler as he departed on his journey." There was a brief silence while the rain still fell heavily, though the sky showed signs of clearing. Then Walter Skinner in his small cracked voice laughed aloud. "The troop will be there, and there will be hard fighting for naught," he said. "For the prize is escaped and we shall capture it and have the reward." "What thinkest thou of Selby?" asked Humphrey, when the two spies had gone on toward the river. "I think thou art right," answered Hugo, frankly. Without a word Humphrey climbed still higher in the tree and gazed after the two till they were hidden from view in the forest. "Hast thou been before in this wood?" he inquired, when he and Hugo had descended and stood upon the ground. "Nay," replied Hugo. "I thought not. Ask me no questions and I will lead thee through it. I know it of old." Hugo at this looked rather resentful. He had regarded himself as the important personage on the journey just undertaken, and now it seemed that the serving-man regarded the important personage as Humphrey. And the boy thought that because Humphrey had been right in his purpose to avoid Selby was no reason why he should assume the charge of the expedition. He did not dispute him, however, but followed the triumphant serving-man back to the thicket, to the horses, his bow and arrows, and his dog.