For a long while he sat on, huddled in the corner of an arm-chair, his elbows on the arm, his chin resting on his hand, and in his eyes the look of one who wrestles with obscure and complicated problems of mental arithmetic. From time to time, but without relaxing his expression of concentrated effort, he stretched out long artistic fingers to a box on the table, took from it a chocolate, and transferred it mechanically to his mouth. He always ate sweets when he had a problem on hand. He was trying to think of some means by which his client could be protected from the mysterious danger that threatened him; that it was a very real danger, Gimblet accepted without question; he had only seen Lord Ashiel twice in his life, but it was quite enough to make him certain that here was a man whom it would take a great deal to alarm. This was no boy crying "wolf" for the sake of making a stir. But the more he thought, the more he saw that there was nothing to be done. A word to the police would suffice, no doubt, to precipitate matters; for, if the Nihilist Society which threatened Lord Ashiel contemplated his destruction, a hint that he might be already taking reciprocal measures would not be likely to make them feel more mercifully towards him. It was obvious that Ashiel would look with suspicion upon any Russian who might approach him, but Gimblet determined to write him a line of warning against foreigners of any description. Still, these societies sometimes had Englishmen amongst their members, and ways of enforcing obedience upon their subordinates which made any decision they might come to as good as carried out almost as soon as it was uttered. The detective's cogitations were disturbed by Higgs, who had returned, and now brought him in some tea. He poured himself out half a cup, which he filled up with Devonshire cream. He had a peculiar taste in food, and was the despair of his excellent cook, but on this occasion he ate none of the cakes and bread and butter she had provided, the chocolates having rather taken the edge off his appetite. From where he sat he could see, through the open window, the broad grey stretches of the river, with a barge going swiftly down on the tide; brown sails turned to gleaming copper by the slanting rays from the West. The hum and rattle of the streets came up to him murmuringly; now and then a train rumbled over Charing Cross Bridge, and the whistle of engines shrilled out above the constant low clamour of the town.