Pulling a bunch of keys from his pocket, the Duke ran up the steps. The inspector followed him. The Duke looked at the bunch, picked out the latch-key, and fitted it into the lock. It did not open it. He drew it out and tried another key and another. The door remained locked. “Let me, your Grace,” said the inspector. “I’m more used to it. I shall be quicker.” The Duke handed the keys to him, and, one after another, the inspector fitted them into the lock. It was useless. None of them opened the door. “They’ve given me the wrong keys,” said the Duke, with some vexation. “Or no—stay—I see what’s happened. The keys have been changed.” “Changed?” said the inspector. “When? Where?” “Last night at Charmerace,” said the Duke. “M. Gournay-Martin declared that he saw a burglar slip out of one of the windows of the hall of the château, and we found the lock of the bureau in which the keys were kept broken.” The inspector seized the knocker, and hammered on the door. “Try that door there,” he cried to his men, pointing to a side-door on the right, the tradesmen’s entrance, giving access to the back of the house. It was locked. There came no sound of movement in the house in answer to the inspector’s knocking. “Where’s the concierge?” he said. The Duke shrugged his shoulders. “There’s a housekeeper, too—a woman named Victoire,” he said. “Let’s hope we don’t find them with their throats cut.” “That isn’t Lupin’s way,” said the inspector. “They won’t have come to much harm.” “It’s not very likely that they’ll be in a position to open doors,” said the Duke drily. “Hadn’t we better have it broken open and be done with it?” The inspector hesitated. “People don’t like their doors broken open,” he said. “And M. Gournay-Martin—” “Oh, I’ll take the responsibility of that,” said the Duke. “Oh, if you say so, your Grace,” said the inspector, with a brisk relief. “Henri, go to Ragoneau, the locksmith in the Rue Theobald. Bring him here as quickly as ever you can get him.” “Tell him it’s a couple of louis if he’s here inside of ten minutes,” said the Duke. The policeman hurried off. The inspector bent down and searched the steps carefully. He searched the roadway. The Duke lighted a cigarette and watched him. The house of the millionaire stood next but one to the corner of a street which ran at right angles to the one in which it stood, and the corner house was empty. The inspector searched the road, then he went round the corner. The other policeman went along the road, searching in the opposite direction. The Duke leant against the door and smoked on patiently. He showed none of the weariness of a man who has spent the night in a long and anxious drive in a rickety motor-car. His eyes were bright and clear; he looked as fresh as if he had come from his bed after a long night’s rest. If he had not found the South Pole, he had at any rate brought back fine powers of endurance from his expedition in search of it.