Tom knew the ladder by the shape: it was the one David borrowed from the next neighbour, against whose long cow-house it always hung on two great pegs, sheltered from the rain by the thick far-projecting thatch.
And now this ladder had been reared up against the mill, and though the top rounds could only be dimly-seen, there they were resting up against the rails of the little gallery, close to the shutter which opened into the roof of the observatory.
“It’s Pete,” Tom said to himself, as he stood listening, but only to hear the beating of his own heart. Then he took three or four steps up very softly, but stopped short, for all at once there was a gleam of light in the panes of the laboratory window, such as would be produced by any one striking a wax-match.
Tom stepped down again, stood looking up a few moments watching the feeble light, which was little more than would have been produced by the gleaming of the stars, and then an idea occurred to him.
Getting behind the ladder he gave it a push, and it rose upright directly, and he found that he had no difficulty in managing it. Working it to and fro he walked its legs close up to the brick wall, and then placing his hands upon the rounds, lowered it step by step till it lay flat in the yard.
“No running away this time,” muttered Tom; and he crept back to the entrance, which he opened softly with the key, entered the workshop, and then closed the door and locked it on the inside, afterwards placing the keys in his pocket, but took them out again, for he remembered, what he had forgotten in his excitement, that since the laboratory had been furnished, it too had been kept locked, so that to get into the chamber where he had seen the gleam of light, he would have to unfasten the door at the top of the flight of steps.
For a brief moment the boy felt nervous, then he was himself again.
“Pete will be in a horrible fright,” he thought; and, creeping up, he softly inserted the key, unlocked this door, and withdrew the key without a sound. Then slowly and silently he pressed down the thumb-latch, the door yielded with a faint creak, and he passed in, to stand listening and looking round.
All was still and very dark, save that he could just make out the shape of the window, and if any one had passed the panes he might have been visible as a black shadow.
For an instant Tom wondered whether he could have been deceived, but the next he knew it was impossible. The light might have been fancy, or a reflection, but there was none about that ladder.