The investigation became embittered like a personal matter.
In fact, were the prisoner innocent, he would become inexcusable in his own eyes; and, in proportion as he reproached himself the more severely, and as the knowledge of his own failings grew, he felt the more disposed to try everything to conquer his former rival, even to abusing his own power.

The logic of events urged him on.

It seemed as though his honour itself was at stake; and he displayed a passionate activity, such as he had never before been known to show in any investigation.
M.Daburon passed all Sunday in listening to the reports of the detectives he had sent to Bougival.
They had spared no trouble, they stated, but they could report nothing new.
They had heard many people speak of a woman, who pretended, they said, to have seen the assassin leave Widow Lerouge's cottage; but no one had been able to point this woman out to them, or even to give them her name.
They all thought it their duty, however, to inform the magistrate that another inquiry was going on at the same time as theirs.

It was directed by M.Tabaret, who personally scoured the country round about in a cabriolet drawn by a very swift horse.

He must have acted with great promptness; for, no matter where they went, he had been there before them.