"That's so. We must be careful."
Very cautiously the two lads dragged the bed to a position below the small window. Then they piled the rickety bureau on that, and on the top of the last-named bit of furniture they stood a chair.
Sandy was the first to clamber up. It was slow work, for the stack of furniture was rickety, and threatened to collapse with a crash at any instant.
But at last he gained the summit and wriggled his active body half through the window. It was too dark outside to see much, and the lad determined on a characteristically bold step. Squirming through the small casement, he let himself drop, holding by his hands to the window-ledge, while he felt about beneath him with his feet.
To his intense joy, he could feel his toe-tips encounter a projection from the wall of the tower, which he judged must be the outside stairway they had noticed.
"Come on!" he called softly to Jack, and then he gently dropped. As he had suspected, he found himself standing on the stairway, which seemed to be staunch and firm.
Sandy tested it by rocking back and forth with his face to the rough wall of the tower. There was no tremor from the stones beneath him.
"Noo, if all goes well, we'll be free again," he muttered to himself, as he awaited Jack's coming.
Presently, in spite of the darkness, he saw the other lad's head projected through the window above him.
"Is it all right?" asked Jack in a low whisper.