Rosalind's hand went to her throat. Instinctively she moved to bar the stairway.
"I wouldn't," she advised hastily. "He might escape."
"Can't," declared Mr. Davidson emphatically. "He's too big to get through an attic window, and if he did manage it he'd drop about forty feet to the ground. Take him up-stairs, James."
"No," said Rosalind firmly.
Mr. Davidson looked at her in surprise.
"I've a better plan," she continued quickly. "Keep him with us. Watch him. Study him. Sometimes they—they betray themselves."
The prisoner regarded her with appealing eyes.
"All right; watch him if you like," assented Mr. Davidson. "Bring him into the library, James."
Not until the last of them had left the hall did Rosalind desert her post at the foot of the staircase. As she moved to follow she gazed swiftly upward, but the boatman was not in sight.
Her mood was a mixture of alarm and irritation. For the life of her she could not understand why Sam committed the folly of seeking a refuge upstairs, when there were easy avenues of escape by the rear of the house. True, he might make his exit by an upper window and across the porch-roof; but it was an extra and a useless hazard. Most amazing was the fact that she did not know whether he was still in the house. She prayed he was not, but feared otherwise. Nobody must go up-stairs until she could be sure.