The warrant for Milburgh's arrest was waiting for them, and placed in the hands of Whiteside for execution. "We'll give him no time," said the officer. "I'm afraid he's had a little too much grace, and we shall be very lucky if we find him at home." As he had suspected, the house in Camden Town was empty, and the woman who came daily to do the cleaning of the house was waiting patiently by the iron gate. Mr. Milburgh, she told them, usually admitted her at half-past eight. Even if he was "in the country" he was back at the house before her arrival. Whiteside fitted a skeleton key into the lock of the gate, opened it (the charwoman protesting in the interests of her employer) and went up the flagged path. The door of the cottage was a more difficult proposition, being fitted with a patent lock. Tarling did not stand on ceremony, but smashed one of the windows, and grinned as he did so. "Listen to that?" The shrill tinkle of a bell came to their ears. "Burglar alarm," said Tarling laconically, and pushed back the catch, threw up the window, and stepped into the little room where he had interviewed Mr. Milburgh. The house was empty. They went from room to room, searching the bureaux and cupboards. In one of these Tarling made a discovery. It was no more than a few glittering specks which he swept from a shelf into the palm of his hand. "If that isn't thermite, I'm a Dutchman," he said. "At any rate, we'll be able to convict Mr. Milburgh of arson if we can't get him for murder. We'll send this to the Government analyst right away, Whiteside. If Milburgh did not kill Thornton Lyne, he certainly burnt down the premises of Dashwood and Solomon to destroy the evidence of his theft." It was Whiteside who made the second discovery. Mr. Milburgh slept on a large wooden four-poster. "He's a luxurious devil," said Whiteside. "Look at the thickness of those box springs." He tapped the side of that piece of furniture and looked round with a startled expression. "A bit solid for a box spring, isn't it?" he asked, and continued his investigation, tearing down the bed valance. Presently he was rewarded by finding a small eyelet hole in the side of the mattress. He took out his knife, opened the pipe cleaner, and pressed the narrow blade into the aperture. There was a click and two doors, ludicrously like the doors which deaden the volume of gramophone music, flew open. Whiteside put in his hand and pulled something out. "Books," he said disappointedly. Then, brightening up. "They are diaries; I wonder if the beggar kept a diary?" He piled the little volumes on the bed and Tarling took one and turned the leaves. "Thornton Lyne's diary," he said. "This may be useful."