"Because we dare not," Ralph murmured. "It is not that we cannot trust you, but because we dare not."
With this Geoffrey was fain to be content. By this time the thread had left the table, and was lying on the floor.
"The other end is tied to Mrs. May's door," Tchigorsky explained. "When that door was cautiously opened, of course, the thread moved. Geoffrey, you stay here. Ralph, will you go up by the back staircase and get up to the corridor. Wait there."
"Is there danger?" Geoffrey whispered.
"Not now," said Tchigorsky, "but this audacity passes all bounds. That woman had planned to strike a blow at the very moment when she was enjoying the hospitality of this roof. The boldness of it would have averted all suspicion from her. One of the family mysteriously disappears and is never heard of again. In the morning not one lock or bolt or bar is disturbed. And yet the member of the family is gone. England would have been startled by the news to-morrow."
"You heard all this?" Geoffrey cried.
"Yes," Tchigorsky said quietly. "That disguise I showed you was useful to me. It is going to be more useful still."
"But the danger! It must be averted," Geoffrey whispered.
Already Tchigorsky was leaving the room. The lamp had been extinguished, after taking care to place a box of matches close beside it. In the darkness Geoffrey waited, tingling to his finger tips with suppressed excitement.
Meanwhile, Tchigorsky felt his way along in the darkness. He was counting his steps carefully. He reached a certain spot and then stopped. Ralph strolled down the back staircase, and thence down a flagged passage into the hall, where he climbed the stairs.