First disguising himself as an old gentleman of private means, strolling about, cane in hand, Lupin spent his time in the neighbourhood, on the benches of the square and the avenue. He made a discovery on the first day. Two men, dressed as workmen, but behaving in a manner that left no doubt as to their aims, were watching the deputy’s house. When Daubrecq went out, they set off in pursuit of him; and they were immediately behind him when he came home again. At night, as soon as the lights were out, they went away.
Lupin shadowed them in his turn. They were detective-officers.
“Hullo, hullo!” he said to himself. “This is hardly what I expected. So the Daubrecq bird is under suspicion?”
But, on the fourth day, at nightfall, the two men were joined by six others, who conversed with them in the darkest part of the Square Lamartine. And, among these new arrivals, Lupin was vastly astonished to recognize, by his figure and bearing, the famous Prasville, the erstwhile barrister, sportsman and explorer, now favourite at the Élysée, who, for some mysterious reason, had been pitchforked into the headquarters of police as secretary-general, with the reversion of the prefecture.
And, suddenly, Lupin remembered: two years ago, Prasville and Daubrecq the deputy had had a personal encounter on the Place du Palais-Bourbon. The incident made a great stir at the time. No one knew the cause of it. Prasville had sent his seconds to Daubrecq on the same day; but Daubrecq refused to fight.
A little while later, Prasville was appointed secretary-general.
“Very odd, very odd,” said Lupin, who remained plunged in thought, while continuing to observe Prasville’s movements.
At seven o’clock Prasville’s group of men moved away a few yards, in the direction of the Avenue Henri-Martin. The door of a small garden on the right of the house opened and Daubrecq appeared. The two detectives followed close behind him and, when he took the Rue-Taitbout train, jumped on after him.
Prasville at once walked across the square and rang the bell. The garden-gate was between the house and the porter’s lodge. The portress came and opened it. There was a brief conversation, after which Prasville and his companions were admitted.
“A domiciliary visit,” said Lupin. “Secret and illegal. By the strict rules of politeness, I ought to be invited. My presence is indispensable.”