"You addressed in cipher a message in an advertisement to someone whom you called `Nello,'" I said. "Who was he?" "The man John Parham. He had always expressed pity for me. To the others he was known as Nello, his real name being Lionel. I was mistaken, however. He was no better than the others. The cipher they had given to me in order that I could communicate with them in secret if occasion demanded." At six o'clock that same evening, after Sybil had returned to her mother's house in Grosvenor Street, I entered the Tottenham Court Road Police Station, and there found Pickering anxiously awaiting me. "I wasn't far wrong, Mr Hughes," he exclaimed quickly. "Parham came to Clipstone Street just before noon, and dropped into Nicholls' hands. Winsloe somehow got wind of the affair, and has bolted--on his way to the Continent, probably. We've circulated his description and hope to get him. But he's a wily bird, it seems, from all accounts. Your friend Domville was a pretty tough customer, too," he added. "Why? I don't quite follow you." "Well, when I got back here and went to his cell I found him stone dead. He'd poisoned himself! Swallowed a strychnine pill." "Because he was the murderer of Arthur Rumbold," I answered. "Miss Burnet will later on explain everything." "H'm," he grunted. "A pretty complicated bit of business, when all the threads are gathered up." There were still a few other matters to investigate, I pointed out, and an hour later we went out to Sydenham Hill, and there saw Mrs Parham and Miss O'Hara. When we told the poor lady of her husband's arrest, and the charge against him, she fainted. Then, presently, when she came to, she confessed that soon after her marriage she had had certain suspicions aroused, for she discovered that her husband was wanted by the French police for some offence committed in Bordeaux. The secret cavity had been made in the drawing-room floor by him, and in it he kept his private papers. Her own opinion was that the agents of French police wanted to search there for certain evidence, the evidence of that gruesome eye, no doubt, but knowing that no English magistrate would grant them a search-warrant they resolved to make a raid on the place, as though they were thieves. Though they overlooked the strange eye which, with some ulterior motive Parham had preserved, they nevertheless secured sufficient evidence to warrant them in applying for the man's extradition for the murder of a banker at Bordeaux, which indeed the French Consulate-General had done three weeks previously. Miss O'Hara, it appeared, had accidentally discovered the cipher hidden behind a heavy wardrobe in one of the bedrooms, and by its means had read my messages and gone to Baker Street and to Dean's Yard out of sheer curiosity.