Marc was unable to get to sleep that night, for he was haunted by the events of the day--by that monstrous, mysterious, puzzling crime. Thus, while Geneviève, his wife, reposed quietly beside him, he dwelt in thought upon each incident of the affair, classified each detail, striving to pierce the darkness and establish the truth. Marc's mind was one that sought logic and light. His clear and firm judgment demanded in all things a basis of certainty. Thence came his absolute passion for truth. In his eyes no rest of mind, no real happiness, was possible without complete, decisive certainty. He was not very learned, but such things as he knew he wished to know completely, in order that he might have no doubt of the possession of the truth, experimental truth, established for ever. All unrest came to an end when doubt ceased; he then fully recovered his spirits, and to his passion for the acquirement of truth was added one for imparting it to others, for driving it into the brains and hearts of all. His marvellous gifts then became manifest; he brought with him a methodical power which simplified, classified, illumined everything. His quiet conviction imposed itself on his hearers, light was shed on dim notions, things seemed easy and simple. He instilled life into the driest subjects. He succeeded in imparting a passionate interest even to grammar and arithmetic, rendering them as interesting as stories to his pupils. In him one really found the born teacher. He had discovered that he possessed that teaching gift at the time when, already possessed of a bachelor's degree, he had come to Beaumont to finish his apprenticeship as a lithographic draughtsman in the establishment of Messrs. Papon-Laroche. Entrusted with the execution of many school diagrams, he had exercised his ingenuity in simplifying them, creating perfect masterpieces of clearness and precision, which had revealed to him his true vocation, the happiness that he found in teaching the young.