The Closed Book by William le Queux

While the rest of the party examined the dungeon, I clambered over the ruins, and ascended by the winding, broken stairway to the summit. I walked with Wyman across the weedy, neglected ground beyond the dried-up fosse, reconstructing the stronghold in imagination by the position of the broken barbican.

Over the self-same ground the unfrocked monk of Crowland had wandered with his companion in misfortune, the monk Malcolm. We looked back at the gateway of the castle, so high up that it was on a level with the second floor. Through that, the only exit from the castle, old Godfrey had fled with his fair charge across the drawbridge, over the island to the river, and across the narrow temporary bridge, then existing, to the shore -- away back to safety in England, leaving Lucrezia's casket, with its precious contents, safely hidden.