Girke turned the leaves of his note-book again. “Here we are, sir. Our investigations provide an unbroken chain. From Kronprinzenufer he moved with the woman concerning whom we have gathered full and reliable data to Bernauer Street, in the neighbourhood of the Stettiner Railroad Station. Next he moved to 16 Fehrbelliner Street; then to No. 3 Jablonski Street; then to Gaudy Street, quite near the Exerzier Square; finally to Stolpische Street at the corner of Driesener. The curious thing is not only this constant change of habitation, but the gradual decline in the character of the neighbourhoods selected, down to a hopelessly proletarian level. This fact seems to reveal a secret plan and a definite intention.” “And he stopped at Stolpische Street?” “He’s been there five weeks, since the twentieth of February. But he rented two flats in this place, one for the woman in question and one for himself.” “This place is far in the north of the city, isn’t it?” “As far as you can get. West and north of it there are empty lots. To the east the roads lead to the cemeteries of Weissensee. All around are factories. It’s an unhealthy, unsafe, and hideous locality. The house itself was built about six years ago, but is already in a deplorable condition. There are forty-five flats with outside light, and fifty-nine with nothing but light from the court. The latter are inhabited by factory hands, hucksters, people of uncertain occupations, and characters that are clearly suspicious. Karen Engelschall, the woman in question, has an outside flat on the third floor, consisting of two rooms and a kitchen. The furnishings belong to a widow named Spindler. The monthly rent is eighty marks, payable in advance. She has a servant, a young girl named Isolde Schirmacher, who is the daughter of a tailor. Your son lodges on the ground-floor of the inside flats with a certain Gisevius, who is night watchman in the Borsig works. His accommodation consists of a barely furnished living-room and a half-dark sleeping chamber in which there is nothing but a cot.” Herr Wahnschaffe’s eyes grew wide, under the influence of a fright which he could not quite control. “For heaven’s sake,” he said, “what can be the meaning of it?” “It is a mystery indeed, sir. We have never had a similar case. There is plenty of room for supposition, of course. Then there’s the hope that future events may throw light on everything.” Herr Wahnschaffe recovered his self-control, and coldly dismissed the other’s attempts at consolation. “And what is your information concerning the woman?” he asked in his most official tone. “What results have you in that direction?”