“Mind,” called Mr. Prescott, when Billy had almost closed the door, “you are to return at half-past four, key or no key.”
“Sure, sir,” answered Billy.
Things don’t always look the same on both sides of a door. Billy found that out as soon as he was alone in the corridor. But Billy had a theory, though Mr. Prescott may have thought that he was joking, and it was built on so firm a foundation that William Wallace offered, at once, to help him work it out.
Billy hadn’t visited Uncle John that day in the foundry simply for nothing. He had it all figured out in his mind that, as soon as the black-haired man had finished using the key for a pattern, he would put it back in the door; and Billy had said four o’clock because that was about the time when the molds were supposed to be ready.
When a man knew as much about molding as Mr. Prescott did, it did seem as if he might have figured that out himself.
Billy looked around for a place where he could hide to watch the door. There wasn’t anybody in sight, so he took plenty of time to decide.
Half-way down the corridor, on the right hand side, was a small closet that had been built up on the floor, by itself, so that Mr. Prescott could have a place to keep his motor clothes.
Billy went into that, and tried, by leaving the door part way open, to fix a crack through which he could watch the door. Finding that the crack was too far out of range, he started down the corridor to find another place.
He had just about decided to try hiding behind the tool room when he heard a step, and, looking up, saw Thomas Murphy, the timekeeper.
“It’s a great relief, William,” said Tom, “to see a friend like you. Does the super know about the key?”