Therefore when I had put Ethelwynn into a cab, and had bade farewell to Sir Bernard and received certain private instructions from him, we walked together into the narrow, rather dirty High Street of Brentford, the county town of Middlesex. The inn we entered was close to a soap works, the odour from which was not conducive to a good appetite, but we obtained a room to ourselves and ate our meal of cold beef almost in silence. "I was up early this morning," Ambler observed at last. "I was at Kew at eight o'clock." "Why?" "In the night an idea struck me, and when such ideas occur I always seek to put them promptly into action." "What was the idea?" I asked. "I thought about that safe in the old man's bedroom," he replied, laying down his knife and fork and looking at me. "What about it? There's surely nothing extraordinary in a man having a safe in his room?" "No. But there's something extraordinary in the key of that safe being missing," he said. "Thorpe has apparently overlooked the point; therefore this morning I went down to Kew, and finding only a constable in charge, I made a thorough search through the place. In the dead man's room I naturally expected to find it, and after nearly a couple of hours searching in every nook and every crack I succeeded. It was hidden in the mould of a small pot-fern, standing in the corridor outside the room." "You examined the safe, then?" "No, I didn't. There might be money and valuables within, and I had no right to open it without the presence of a witness. I've waited for you to accompany me. We'll go there after luncheon and examine its contents." "But the executors might have something to say regarding such an action," I remarked. "Executors be hanged! I saw them this morning, a couple of dry-as-dust old fossils--city men, I believe, who only think of house property and dividends. Our duty is to solve this mystery. The executors can have their turn, old chap, when we've finished. At present they haven't the key, or any notion where it is. One of them mentioned it, and said he supposed it was in the widow's possession." "Well," I remarked, "I must say that I don't half like the idea of turning out a safe without the presence of the executors." "Police enquiries come before executors' inventories," he replied. "They'll get their innings all in good time. The house is, at present, in the occupation of the police, and nobody therefore can disturb us." "Have you told Thorpe?" "No. He's gone up to Scotland Yard to make his report. He'll probably be down again this afternoon. Let's finish, and take the ferry across." Thus persuaded I drained my ale, and together we went down to the ferry, landing at Kew Gardens, and crossing them until we emerged by the Unicorn Gate, almost opposite the house.