The Turnpike House by Fergus Hume — Read

Ruth could not rid herself of a haunting doubt that her father knew more of the Jenner murder than he chose to confess. If he himself had not killed the man in a fit of impetuous rage -- and the girl could not bring herself to think this -- he knew who had struck the fatal blow. Ruth was certain now that Mrs. Jenner was innocent, notwithstanding the fact that she had been found guilty. This being so, she argued to herself that if her father were aware of the truth he should at once take steps to remedy the grave miscarriage of justice which had taken place. But as he made no move, Ruth, perplexed and doubtful, became quite ill with suspense. It was no wonder then that Geoffrey had found her poor company, and had failed to understand her constant melancholy. Under these circumstances he had taken his departure, wondering what had befallen the house which had formerly been so bright and pleasant. But no satisfaction was to be had either from Mr. Cass or from his daughter.

On arriving at his own place he went at once to the library to look for some document with his father's signature in order to compare it with that on the bill. And after a close inspection of some half-dozen autographs of the late Mr. Heron, he came to the conclusion that the signature to the bill was a forgery. Once convinced of this, he began to see daylight, and argued out the case that evening, alone and undisturbed.