M. Nicole's accusation, therefore, was receiving an early proof. Unfortunately - and Lupin was no more successful in his own attempts - it was impossible to obtain the least clue as to the motor-car, the chauffeur and the four people who had entered Daubrecq's house. Were they associates of the marquis, compromised in the canal affair like himself? Were they men in his pay? Nobody knew.

The whole search, consequently, had to be concentrated upon the marquis and the country-seats and houses which he might possess at a certain distance from Paris, a distance which, allowing for the average speed of a motor-car and the inevitable stoppages, could be put at sixty to ninety miles.

Now d'Albufex, having sold everything that he ever had, possessed neither country-houses nor landed estates.

They turned their attention to the marquis' relations and intimate friends. Was he able on this side to dispose of some safe retreat in which to imprison Daubrecq?

The result was equally fruitless.

And the days passed. And what days for Clarisse Mergy! Each of them brought Gilbert nearer to the terrible day of reckoning. Each of them meant twenty-four hours less from the date which Clarisse had instinctively fixed in her mind. And she said to Lupin, who was racked with the same anxiety:

"Fifty-five days more... Fifty days more... What can one do in so few days?... Oh, I beg of you... I beg of you... "

What could they do indeed? Lupin, who would not leave the task of watching the marquis to any one but himself, practically lived without sleeping. But the marquis had resumed his regular life; and, doubtless suspecting something, did not risk going away.

Once alone, he went down to the Duc de Montmaur's, in the daytime. The duke kept a pack of boar-hounds, with which he hunted the Forest of Durlaine. D'Albufex maintained no relations with him outside the hunt.

"It is hardly likely," said Prasville, "that the Duc de Montmaur, an exceedingly wealthy man, who is interested only in his estates and his hunting and takes no part in politics, should lend himself to the illegal detention of Daubrecq the deputy in his chateau."

Lupin agreed; but, as he did not wish to leave anything to chance, the next week, seeing d'Albufex go out one morning in riding-dress, he followed him to the Gare du Nord and took the same train.

He got out at Aumale, where d'Albufex found a carriage at the station which took him to the Chkteau de Montmaur.

Lupin lunched quietly, hired a bicycle and came in view of the house at the moment when the guests were going into the park, in motor-cars or mounted. The Marquis d'Albufex was one of the horsemen.

Thrice, in the course of the day, Lupin saw him cantering along. And he found him, in the evening, at the station, where d'Albufex rode up, followed by a huntsman.

The proof, therefore, was conclusive; and there was nothing suspicious on that side. Why did Lupin, nevertheless, resolve not to be satisfied with appearances? And why, next day, did he send the Masher to find out things in the neighbourhood of Montmaur? It was an additional precaution, based upon no logical reason, but agreeing with his methodical and careful manner of acting.