‘Ah, Monday.’ Lefarge pretended to correct his notes. ‘Monday evening, of course. M. Boirac was at home on Sunday night, but he did not unpack it till Monday. That’s right, I think?’

‘That’s right.’

‘Then on Tuesday he went to Belgium, and returned home on Thursday evening?’

‘Correct, monsieur.’

‘Thanks very much. I’m glad you noticed that slip. I’ve got it right now, I think.’

He remained conversing for a few minutes, making himself agreeable to the old man and telling him some of the adventures he had met with during his career. The more he saw of François, the more he came to respect him, and he felt increasingly certain the old man’s statement was to be believed and that he would not lend himself to anything dishonourable.

As if to balance the successes of the morning, during the whole of the afternoon Lefarge drew blank. After leaving the house in the Avenue de l’Alma, he questioned the clerks in the left luggage office at the Gare du Nord. Here he could get no information at all. No one remembered François putting in the bag, nor Boirac claiming it, nor could any record of the bag itself be turned up. Again, in the Place de la Bastille, where he spent some hours interviewing the waiters in the various restaurants, both in the Place itself and close by in the diverging streets, no better luck attended his efforts. He could find no trace of Boirac’s having dined in any of them.

All the same, he was well satisfied with his day’s work. The information he had got was definite and valuable, in fact, he thought it conclusively established the truth of Boirac’s statement, at least in as far as Tuesday was concerned. If he could do as well in connection with the Wednesday and Thursday, he thought the manufacturer’s alibi would stand, and his innocence of the murder must then be admitted.

To carry on the inquiry, he would have to visit Brussels, and he accordingly telephoned to the Gare du Nord engaging a berth on the 11.20 p.m. sleeping car train that night. Then, after calling up the Sûreté, he turned his steps homewards to dine and have a rest till it was time to start.

He made a comfortable journey, and, having breakfasted in one of the cafés in the Place du Nord in Brussels, took an early train to Malines. He presented himself at the post office and asked if he could be directed to the residence of M. Armande Boirac. The clerk knew the name, though he was not certain of the address, but after inquiries at two or three of the principal shops, the detective found one at which M. Boirac dealt.