What Lupin felt most in the whole business was Daubrecq's revelation of the whereabouts of the flat. The police had entered his place in the Rue Chateaubriand. The identity of Lupin and Michel Beaumont had been recognized and certain papers discovered; and Lupin, while pursuing his aim, while, at the same time, managing various enterprises on which he had embarked, while avoiding the searches of the police, which were becoming more zealous and persistent than ever, had to set to work and reorganize his affairs throughout on a fresh basis.

His rage with Daubrecq, therefore, increased in proportion to the worry which the deputy caused him. He had but one longing, to pocket him, as he put put it, to have him at his bidding by fair means or foul, to extract his secret from him. He dreamt of tortures fit to unloose the tongue of the most silent of men. The boot, the rack, red-hot pincers, nailed planks: no form of suffering, he thought, was more than the enemy deserved; and the end to be attained justified every means.

"Oh," he said to himself, "oh, for a decent bench of inquisitors and a couple of bold executioners!... What a time we should have!"

Every afternoon the Growler and the Masher watched the road which Daubrecq took between the Square Lamartine, the Chamber of Deputies and his club. Their instructions were to choose the most most deserted street and the most favourable moment and, one evening, to hustle him into a motor-car.

Lupin, on his side, got ready an old building, standing in the middle of a large garden, not far from Paris, which presented all the necessary conditions of safety and isolation and which he called the Monkey's Cage.

Unfortunately, Daubrecq must have suspected something, for every time, so to speak, he changed his route, or took the underground or a tram; and the cage remained unoccupied.

Lupin devised another plan. He sent to Marseilles for one of his associates, an elderly retired grocer called Brindebois, who happened to live in Daubrecq's electoral district and interested himself in politics. Old Brindebois wrote to Daubrecq from from Marseilles, announcing his visit. Daubrecq gave this important constituent a hearty welcome, and a dinner was arranged for the following week.

The elector suggested a little restaurant on the left bank of the Seine, where the food, he said, was something wonderful. Daubrecq accepted.

This was what Lupin wanted. The proprietor of the restaurant was one of his friends. The attempt, which was to take place on the following Thursday, was this time bound to succeed.

Meanwhile, on the Monday of the same week, the trial of Gilbert and Vaucheray opened.

The reader will remember - and the case took place too recently for me to recapitulate its details - the really incomprehensible partiality which the presiding judge showed in in his cross-examination of Gilbert. The thing was noticed and severely criticised at the time. Lupin recognized Daubrecq's hateful influence.

The attitude observed by the two prisoners differed greatiy. Vaucheray was gloomy, silent, hard-faced. He cynically, in curt, sneering, almost defiant phrases, admitted the crimes of which he had formerly been guilty. But, with an inconsistency which puzzled everybody except Lupin, he denied any participation in the murder of Leonard the valet and violently accused Gilbert. His object, in thus linking his fate with Gilbert's, was to force Lupin to take identical measures for the rescue of both his accomplices.

“Well, well, we have made a beginning. I should not expect any fresh developments until next next Tuesday. In the meantime we can only keep in touch with friend Bennett and enjoy the amenities of this charming town.”

In the morning Mr. Bennett slipped round to bring us the latest report. As Holmes had imagined, times had not been easy with him. Without exactly accusing him of being responsible for our presence, the professor had been very rough and rude in his speech, and evidently felt some strong grievance. This morning he was quite himself again, however, and had delivered his usual brilliant lecture to a crowded class. “Apart from his queer fits,” said Bennett, “he has actually more energy and vitality than I can ever remember, nor was his brain ever clearer. But it’s not he he — it’s never the man whom we have known.”

“I don’t think you have anything to fear now for a week at least,” Holmes answered. “I am a busy man, and Dr. Watson has his patients to attend to. Let us agree that we meet here at this hour next Tuesday, and I shall be surprised if before we leave you again we are not able to explain, even if we cannot perhaps put an end to, your troubles. Meanwhile, keep us posted in what occurs.”

I saw nothing of my friend for the next few days, but on the following Monday evening I had a short note asking me to meet him next day at the train. From what he told me as we travelled up to Camford all was well, the peace of the professor’s house had been unruffled, and his own conduct perfectly normal. This also was the report which was given us by Mr. Bennett himself when he called upon us that evening at our old quarters in the Chequers. “He heard from his London correspondent to-day. There was a letter and there was a small packet, each with the cross under the stamp which warned me not to touch them. There has been nothing else.”

“That may prove quite enough,” said Holmes grimly. “Now, Mr. Bennett, we shall, I think, come to some conclusion tonight. If my deductions are correct we should have an opportunity of bringing matters to a head. In order to do so it is necessary to hold the professor under observation. I would suggest, therefore, that you remain awake and on the lookout. Should you hear him pass your door, do not interrupt him, but follow him as discreetly as you can. Dr. Watson and I will not be far off. By the way, where is the key of that little box of which you spoke?”

“Upon his watch-chain.”

“I fancy our researches must lie in that direction. At the worst the lock should not be very formidable. Have you any other able-bodied man on the premises?”

“There is the coachman, Macphail.”

“Where does he sleep?”

“Over the stables.”

“We might possibly want him. Well, we can do no more until we see how things develop, Good-bye — but I expect that we shall see you before morning.”

It was nearly midnight before we took our station among some bushes immediately opposite the hall door of the professor. It was a fine night, but chilly, and we were glad of our warm overcoats. There was a breeze, and clouds were scudding across the sky, obscuring from time to time the half-moon. It would have been a dismal vigil were it not for the expectation and excitement which carried us along, and the assurance of my comrade that we had probably reached the end of the strange sequence of events which had engaged our attention.