Mad Barbara by Warwick Deeping

John Gore made his retreat from Thorn with nothing more threatening in the way of a betrayal than a low, querulous growl from the mastiff chained in the yard. He scaled the gate, and made his way back to the thorn-tree where he had left his heavier clothes and his sword.

Now the sea-captain's brain might have been a Spanish treasure-ship, and the happenings of the night so many buccaneers by the way they stormed in and put everything to confusion. There were a hundred questions to be asked and answered, and many of them were the worst of riddles. The night sky seemed full of new meanings, new mysteries, new secrets, and Thorn itself a strange dim place where the heart of a man might lose itself in wonder. Yet one truth shone out like a great star above the tower, steady and sure amid so many drifting clouds. He had found the girl with the white face and the dusky hair, and learned that she was no more mad than he was; and for that he gave God thanks.