Accordingly he called at the house in the Avenue de l’Alma and saw François. He was surprised to find the old man genuinely grieved at the news of Felix’s arrest. Few though the occasions had been in which the two had met, something in the personality of the former had in this case, as in so many others, inspired attachment and respect. La Touche therefore adopted the same tactics as with the waiter, and, on his explaining that he was acting for the suspected man, he found François anxious to give all the help in his power. But here again all that La Touche gained was confirmation of Boirac’s statement. François recollected the telephone message, and he was sure Boirac had spoken. He positively recognised the voice and equally positively he remembered the day. It was Tuesday. He was able to connect it with a number of other small events which definitely fixed it. ‘Lefarge was right,’ thought the detective, as he strolled up the Avenue de l’Alma. ‘Boirac telephoned from Charenton at 2.30 on Tuesday. However, I may as well go through with the business.’ He turned his steps therefore towards the head office of the Avrotte Pump Construction Company. Repeating Lefarge’s tactics, he watched till he observed Boirac leave. Then he entered the office and asked if he could see M. Dufresne. ‘I am afraid not, monsieur. I believe he has gone out,’ answered the clerk who had come over to attend to him. ‘But if you will take a seat for a moment I shall ascertain.’ La Touche did as he was asked, looking admiringly round the large office with its polished teak furniture, its rows of vertical file cabinets, its telephones, its clicking typewriters, and its industrious and efficient-looking clerks. Now La Touche was not merely a thinking machine. He had his human side, and, except when on a hot scent, he had a remarkably quick eye for a pretty girl. Thus it was that as this eye roamed inquisitively over the room, it speedily halted at and became focused on the second row of typists, a girl of perhaps two or three-and-twenty. She looked, it must be admitted, wholly charming. Small, dark, and evidently vivacious; she had a tiny, pouting mouth and an adorable dimple. Plainly dressed as became her businesslike surroundings, there was, nevertheless, a daintiness and chicness about her whole appearance that would have delighted an even more critical observer than the detective. She flashed an instantaneous glance at him from her dark, sparkling eyes, and then, slightly elevating her pert little nose, became engrossed in her work. ‘I am sorry, monsieur, but M. Dufresne has gone home slightly indisposed. He expects to be back in a couple of days, if you could conveniently call again.’ La Touche hardly felt a proper appreciation of the clerk’s promptness, but he thanked him politely and said he would return later. Then, with a final glance at an averted head of dark, luxuriant hair, he left the office.