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 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 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 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 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 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, that is not unknown among stepmothers. A posthumous jealousy, we will say. Is the lady jealous by nature?”

“Yes, she is very jealous — jealous with all the strength of her fiery tropical love.”

“But the boy — he is fifteen, I understand, and probably very developed in mind, since his body has been circumscribed in action. Did he give you no explanation of these assaults?”

“No, he declared there was no reason.”

“Were they good friends at other times?”

“No, there was never any love between them.”

“Yet you say he is affectionate?”

“Never in the world could there be so devoted a son. My life is his life. He is absorbed in what I say or do.”

Once again Holmes made a note. For some time he sat lost in thought.

“No doubt you and the boy were great comrades before this second marriage. You were thrown very close together, were you not?”

“Very much so.”

“And the boy, having so affectionate a nature, was devoted, no doubt, to the memory of his mother?”

“Most devoted.”

“He would certainly seem to be a most interesting lad. There is one other point about these assaults. Were the strange attacks upon the baby and the assaults upon yow son at the same period?”

“In the first case it was so. It was as if some frenzy had seized her, and she had vented her rage upon both. In the second case it was only Jack who suffered. Mrs. Mason had no complaint to make about the baby.”

“That certainly complicates matters.”

“I don’t quite follow you, Mr. Holmes.”

“Possibly not. One forms provisional theories and waits for time or fuller knowledge to explode them. A bad habit, Mr. Ferguson, but human nature is weak. I fear that your old friend here has given an exaggerated view of my scientific methods. However, I will only say at the present stage that your problem does not appear to me to be insoluble, and that you may expect to find us at Victoria at two o’clock.”

It was evening of a dull, foggy November day when, having left our bags at the Chequers, Lamberley, we drove through the Sussex clay of a long winding lane and finally reached the isolated and ancient farmhouse in which Ferguson dwelt. It was a large, straggling building, very old in the centre, very new at the wings with towering Tudor chimneys and a lichen-spotted, high-pitched roof of Horsham slabs. The doorsteps were worn into curves, and the ancient tiles which lined the porch were marked with the rebus of a cheese and a man after the original builder. Within, the ceilings were corrugated with heavy oaken beams, and the uneven floors sagged into sharp curves. An odour of age and decay pervaded the whole crumbling building.

There was one very large central room into which Ferguson led us. Here, in a huge old-fashioned fireplace with an iron screen behind it dated 1670, there blazed and spluttered a splendid log fire.