There was a side entrance to 404A, which was the newspaper shop that Foyle had cause to remember. He struck the grimy panel sharply with his fist and waited. There was no reply. Again he knocked, and Green, unbuttoning his greatcoat, flung it off and laid it across his arm. He could drop it easily in case of an emergency. Still there was no answer to the knock. "Luckily I swore out a search warrant," muttered Foyle, and searched in his own pockets for something. It was a jemmy of finely tempered steel gracefully curved at one end. He inserted it in a crevice of the door and, leaning his weight upon it, obtained an irresistible leverage. There was a slight crack, and it swung inwards as the screws of the hasp drew. The two men stepped within and, closing the door, stood absolutely still for a matter of ten minutes. Not a sound betrayed that their burglarious entry had alarmed any one. Presently Green made a movement, and a vivid shaft of light from a pocket electric lamp played along the narrow uncarpeted passage. The superintendent gripped his jemmy tightly and turned towards the dirty stairs. Then the light vanished as quickly as it had flared up, and from above there came a sound of shuffling footsteps. Even Heldon Foyle, whom no one would have accused of nervousness, felt his heart beat a trifle more quickly. He knew that if he were as near the heart of the mystery as he believed any second might see shooting. Penned as he and his companion were in the narrow space of the passage barely three feet wide, a shot fired from above could scarcely miss. Crouching low, he sprang up the narrow staircase in three bounds, making scarcely a sound. On the landing above he wound his arms tightly about the person whose movements he had heard and whispered a quick, tense command. "Not a word, or it will be the worse for you. Let's have a light, Green." The prisoner kept very still, and Green flashed a light on his face. It was that of a man of forty or so, with pronounced Hebrew features. His greasy black hair was tangled in coarse curls, and a smooth black moustache ran across his upper lip. A pair of shifty eyes were fixed fearfully on Foyle, and the man murmured something in a guttural tongue. "We are police officers. How many people are there in this house?" demanded Foyle sternly, in a low voice. "You may as well answer in English. Quietly, now." He had released his hold round the Jew's waist, but stood with the jemmy dangling by his side and with ears cocked ready for any sound. Green had climbed the stairs and stood by his side. Domiciliary visits are unfrequent in England, but the Jew was not certain enough to stand upon a legal technicality. As a matter of fact, the search warrant would have met the difficulty. He cringed before the two men, whose faces he could not see, for Green had thrown his wedge of light so that it showed up the man's sallow face and left all else in darkness.