They got back to the main street a block farther on and a few minutes’ walk brought them in sight of the main entrance to the school. “We don’t want to stay around too long,” said Willard. “It’s nearly eight o’clock now.” “Guess we’ll have to do one more and call it a day,” replied Bob. “I never saw such a punk town for--for decorative purposes!” Three Hillsport fellows, returning to school, overtook them as they neared the entrance and, as it seemed, viewed them very, very suspiciously. But the four kept their heads down, and Cal, now carrying the pot of paint, was careful to keep it hidden. The three entered the school grounds and were lost to sight and the conspirators breathed more freely. The wide street ended at the campus. A cross street ran right and left and for a block in each direction the high iron fence of the school bore it company. From the right the street car line came, turning in front of the gate. As, however, they had seen but one car since they had started forth on their expedition, interruption from that source seemed unlikely. The brick wall of which Martin had spoken could not have been placed more advantageously. It surrounded the small premises of a residence on the left-hand corner, and, as Bob triumphantly pointed out, a sign painted there would be the first thing seen by anyone coming through the school gate. “That’s all right,” returned Cal dubiously, “but it’s awfully light here.” And so it was, for just inside the gate an electric arc lamp shed its blue radiance afar. “I’ll stand at the gate,” volunteered Bob, “and Mart and Brand can watch the streets. If anyone comes we’ll whistle.” “What about the folks in the house?” Cal’s enthusiasm was rapidly waning. The residence was brightly lighted and the strains of a piano came forth. “They can’t see through the wall, you lunkhead,” answered Bob, “and if anyone comes out we’ll see ’em and let you know. All you need to do then is set the paint pot down and just walk away, careless-like.” “We-ell, but you fellows watch,” said Cal resignedly. Bob posted himself across the street at the entrance and Martin and Willard took up positions from where they could see anyone approaching on either street. Then Cal set to work. Painting on the rough surface of a brick wall is not so simple as painting on wood, and Cal made slow progress. Now and then the others heard disgusted murmurs from where, a darker form against the shadows, he stooped at his task. Several minutes passed, and Willard, concerned with the fact that train time was approaching, grew nervous; which, perhaps, accounted for a momentary lapse from watchfulness. At all events, the approaching pedestrian, coming along on the school side of the cross street, was scarcely a dozen yards distant when Willard saw him. The latter’s warning might, it seemed, have been heard a mile away. “Beat it!” yelled Willard.