“You say that Mr. Colburn filled the pipe as soon as he got home, and put it in the usual place,” said Mr. Ludgrove slowly. “It was lying there until two o’clock on Saturday. Anybody might have tampered with it in the meanwhile. The cash register, and I suppose the shelf where the pipe was kept, is within easy reach of anybody coming into the shop.”

“I’m afraid that won’t work,” replied Mr. Copperdock, shaking his head. “There’s not one in a thousand as goes into the shop that know’s the pipe’s there. You didn’t yourself till I told you just now, yet you say you’re a regular customer. No, if that pipe was tampered with, it was somebody on the other side of the counter what did it.”