‘Well, keep a good look-out, and if you see him again find out who he is and let me know. Here is my address. If you do that there will be fifty francs for you.’ Lefarge handed over a couple of five-franc pieces and the detectives left, followed by the promises and thanks of the men. ‘I suppose an advertisement for the carter is the next scheme,’ said Burnley, as they walked back in the Clichy direction. ‘We had better report to headquarters, I think,’ replied Lefarge, ‘and see what the Chief advises. If he approves, we might get our advertisement into to-night’s papers.’ Burnley agreed, and when they had had some lunch they rang up the Sûreté from the nearest call office. ‘That Lefarge?’ was the answer. ‘The Chief wants you to return immediately. He’s got some news.’ They took the Metro from Clichy to Châtelet and reached the Sûreté as the clocks were striking two. M. Chauvet was in. ‘Ah,’ he said, as they entered, ‘we’ve had a reply to the dress advertisement. Madame Clothilde’s people near the Palais Royal rang up about eleven saying they believed they had supplied the dress. We got hold of Mlle. Lecoq, who was working it, and sent her over, and she returned here about an hour ago. The dress was sold in February to Madame Annette Boirac, at the corner of Avenue de l’Alma and rue St. Jean, not far from the American Church. You’d better go round there now and make some inquiries.’ ‘Yes, monsieur,’ said Lefarge, ‘but before we go there is this question of the cask,’ and he told what they had learned, and suggested the advertisement about the carter. M. Chauvet had just begun his reply when a knock came to the door and a boy entered with a card. ‘The gentleman’s waiting to see you on urgent business monsieur,’ he said. ‘Hallo!’ said the Chief, with a gesture of surprise. ‘Listen to this.’ He read out the words, ‘“M. Raoul Boirac, rue St. Jean, 1, Avenue de l’Alma.” This will be Mme. Annette B.’s husband, I presume. These advertisements are doing well. You had better stop, both of you,’ and then to the boy, ‘Wait a moment.’ He picked up the telephone, pressing one of the buttons on the stand. ‘Send Mlle. Joubert here immediately.’ In a few moments a girl stenographer entered. M. Chauvet pointed to a corner of the room where Burnley had noticed a screen, set back as if to be out of the way. ‘I want every word of this conversation, mademoiselle,’ said the Chief. ‘Please be careful to miss none of it, and also to keep quiet.’ The girl bowed and, having seen her settled behind the screen, the Chief turned to the messenger. ‘I’ll see him now.’ In a few seconds M. Boirac entered the room. He was a strongly built man of rather under middle age, with thick black hair and a large moustache. On his face was an expression of strain, as if he was passing through a period of acute bodily or mental pain. He was dressed entirely in black and his manner was quiet and repressed.