True, he knew the secret of the crystal stopper. But how was he to know that Daubrecq would not change or had not already changed his tactics? How was he to know that the list of the Twenty-seven was still inside that crystal stopper or that the crystal stopper was still inside the object where Daubrecq had first hidden it?

And there was a further serious reason for alarm in the fact that Clarisse Mergy thought that she was shadowing and watching Daubrecq at a time when, on the contrary, Daubrecq was watching her, having her shadowed and dragging her, with diabolical cleverness, toward the places selected by himself, far from all help or hope of help.

Oh, Daubrecq's game was clear as daylight! Did not Lupin know the unhappy woman's hesitations? Did he not know - and the Growler and the Masher confirmed it most positively - that Clarisse looked upon the infamous bargain planned by Daubrecq in the light of a possible, an acceptable thing? In that case, how could he, Lupin, succeed? The logic of events, so powerfully moulded by Daubrecq, led to a fatal result: the mother must sacrifice herself and, to save her son, throw her scruples, her repugnance, her very honour, to the winds!

"Oh, you scoundrel!" snarled Lupin, in a fit of rage. "If I get hold of you, I'll make you dance to a pretty tune! I wouldn't be in your shoes for a great deal, when that happens."

They reached Monte Carlo at three o'clock in the afternoon. Lupin was at once disappointed not to see Clarisse on the platform at the station.

He waited. No messenger came up to him.

He asked the porters and ticket-collectors if they had noticed, among the crowd, two travellers answering to the description of Daubrecq and Clarisse. They had not.

He had, therefore, to set to work and hunt through all the hotels and lodging-houses in the principality. Oh, the time wasted!

By the following evening, Lupin knew, beyond a doubt, that Daubrecq and Clarisse were not at Monte Carlo, nor at Monaco, nor at the Cap d'Ail, nor at La Turbie, nor at Cap Martin.

"Where can they be then?" he wondered, trembling with rage.

At last, on the Saturday, he received, at the poste restante, a telegram which had been readdressed from the Hotel Franklin and which said:

"He got out at Cannes and is going on to San Remo, Hotel Palace des Ambassadeurs.

"CLARISSE."

The telegram was dated the day before.

"Hang it!" exclaimed Lupin "They passed through Monte Carlo. One of us ought to have remained at the station. I did think of it; but, in the midst of all that bustle... "

Lupin and his friends took the first train for Italy.

They crossed the frontier at twelve o'clock. The train entered the station at San Remo at twelve-forty.

They at once saw an hotel-porter, with "Ambassadeurs-Palace" on his braided cap, who seemed to be looking for some one among the arrivals.

Lupin went up to him:

"Are you looking for M. Nicole?"

"Yes, M. Nicole and two gentlemen."

"From a lady?"

"Yes, Mme. Mergy."

"Is she staying at your hotel?"