He stepped down into a courtyard surrounded by nearly bare walls. It had once been the _patio_ of a private home of some charm. Now, however, it was bleak and empty. A few discouraged flowers grew weedily in one corner. The glow of light in the sky overhead assured Bell that he was in the very heart of Buenos Aires, but only the most subdued of rumbles spoke of the activity and the traffic of the city going on without. "This way," said the man with the expressionless voice. The other man followed. The chauffeur of the car stood aside as if some formality required him neither to start the motor or return to his seat until Bell was clear of the courtyard. Through a heavy timber door. Along a passageway with the odor of neglect. Up stairs which once had been impressive and ornamental. Into a room without windows. "You will have an interview with the Senorita Canalejas in five minutes," said the emotionless voice. The door closed, while Bell found every separate muscle in his body draw taut. And while his brain at first was dazed with incredulous relief, then it went dark with a new and ghastly terror. "They know _yague_," he heard himself saying coldly, "which makes any person obey any command. They may know other and more hellish ones yet." * * * * * He fought for self control, which meant the ability to conceal absolutely any form of shock that might await him. That one was in store he was certain. He paced grimly the length of the room and back again.... Something on the carpet caught his eye. A bit of string. He stared at it incredulously. The end was tied into a curious and an individual knot, which looked like it might be the pastime of a sailor, and which looked like it ought to be fairly easy to tie. But it was one of those knots which wandering men sometimes tie absent mindedly in the presence of stirring events. It was the recognition-knot of the Trade, one of those signs by which men may know each other in strange and peculiar situations. And there were many other knots tied along the trailing length of the string. It seemed as if some nervous and distraught prisoner in this room might have toyed abstractedly with a bit of cord. Only, Bell drew it through his fingers. Double knot, single knot, double knot.... They spelled out letters in the entirely simple Morse code of the telegrapher, if one noticed. "RBRA GN ON PLA HRE ST TGT J." Your old-time telegrapher uses many abbreviations. Your short-wave fan uses more. Mostly they are made by a simple omission of vowels in normal English words. And when the recognition sign at the beginning was considered, the apparently cryptic letters leaped into meaning. "RiBeRA GoNe ON PauLA HeRe SiT TiGhT Jamison." When the door opened again and a terribly pale Paula was ushered in, Bell gave no sign of surprise. He simply took her in his arms and kissed her, holding her very, very close. CHAPTER XIV