Tiptoeing, she came to the sill. Her ears were quick to distinguish sounds of any character. There _was_ a strange, faint creaking not far from that wide-open casement. She could not thrust her head between the bars now (she remembered vividly the last time she had done that and got stuck, and had to shriek for Daddy to come and help her out), but she could press her face close against them and stare into the blackness of the outer world. There! something stirred. Her eyes, growing more accustomed to the darkness, caught the shadow of something writhing in the air. What could it be? Was it alive? A man, or---- Then the bulk of it passed higher, and the strange creaking sound was renewed. Frances almost cried aloud! It was the man she had before seen. He was mounting directly into the air. The over-thrust of the ranch-house roof made the shadow very thick against the house-wall. The man was swinging in the air just beyond this deeper shadow. "What can he be doing?" Frances thought. She had almost spoken the question aloud. But she did not want to startle him--not yet. First, she must learn what he was about. Then she would run and tell her father. This night raider was dangerous--there was no doubt of that. "Oh!" quavered Frances, suddenly, and under her breath. The uncertain bulk of the man hanging in the air had disappeared! For a minute she could not understand. He had disappeared like magic. His very corporeal body--and she noted that it had been bulky when she first saw him roll over the edge of the veranda roof and sit up--had melted into thin air. And then she saw something swinging, pendulum-like, before her. She thrust an arm between the bars and seized the thing. It was a rope ladder. The whole matter, then, was as plain as daylight. The man had climbed to the porch roof, with the rope ladder wound around his body. That was what had made him seem so bulky. Selecting this spot as a favorable one, he had flung the grappling-hook over the eaves. There must be some break in the slates which held the hook. Once fastened there, the man had quickly worked his way up to the roof, and Frances had arrived just in time to see him squirm out of sight. There were a dozen questions in Frances' mind. How did he get here? Who was he? What did he want? Was he the man Captain Rugley had seemed to be expecting to try to make a raid upon the ranch-house? Was he alone? How did he know he could make the hook of his ladder fast at this point? Was there a traitor about who had broken a slate in the roof? Or was the broken place the result of an accident, and the marauder had noted it by daylight from the ground? Question after question flashed through her mind. But there was one query far more important than all the others: Where was the man going over the roof? Frances let the ladder swing away from her clutch again. If she held it the fellow above might become alarmed.