nine o'clock
He was to pull on the string till the rope came into his hand , and to hold that tight until they were over . Vincent chose this spot because it was equally removed from the sentry-boxes at the corners of the yard , and because there was a stone seat in the yard to which one end of the rope could be attached . That night was fine , but the next was thick and misty . At nine o'clock all were in bed , and he lay listening to the clocks in the distance . Ten struck , and eleven , and when he thought it was approaching twelve he got up and crept to the window . He was joined immediately by the others ; the turn-screw was set to work ; and , as he expected , Vincent found no trouble whatever with the screws , which were not yet rusted in the wood , and turned immediately when the powerful screw-driver was applied to them . When all were out the bar was carefully lifted from its place and laid upon the floor .