"Hum! Hum!" he muttered; "the devil," and he looked up at the ceiling, having replaced his eyeglass with a pair of spectacles. Then he took the lamp from Balthazar and placed it on the secrétaire, removing the shade; and this movement suddenly revealed to him a clue which had entirely escaped their attention until now.
CHAPTER V.
An old knife, a gift from a friend in the Dutch Indies, was driven into the wainscoting, about three feet above the secrctaire and half-way between the floor and the ceiling.
Now, what was that old knife doing there?
A few hours previous to this discovery it was lying safe and snug in Balthazar's desk.
At the same moment Tricamp drew attention to the fact that the wire which was attached to the bell was twisted and broken and was fastened about the handle of the knife. He sprang upon a chair, and from there to the top of the desk, from whence he proceeded to examine this bit of fresh evidence.
Suddenly he gave a cry of triumph. He only had to raise his hand between the knife and the picture moulding to ascertain that a large piece of wall paper had been cut out, together with the wood and the plastering, the whole being replaced with a care to defy the closest inspection.
