And so Juliet kept her ground, blushing at her role of spy, and averting her eyes as Julia dropped the book she was holding and ran forward to meet Mark, with that tell-tale look upon her face.

But Mark did not show the same pleasure. He stood, holding the handle of the door, which he had closed gently behind him, and looking with a certain sternness at the girl.

"Julia," he said, "you here! What are you doing?"

"Oh, Mark," she cried, not answering his question, "aren't you glad to see me? It is so long, oh, it is so long since I saw you!"

She threw her arms round his neck with a happy laugh, and drew his face down to hers.

"Darling! darling!" she murmured. "How can we live without each other for one single day!"

She spoke in a low, soft voice. To Juliet, to whom every purling syllable was painfully audible, it sounded cooingly, like the voice of doves.

To the surprise of the girl to whom Mark had proposed marriage two days before, when she ventured to peep through her spy window, Mark's arms were round Julia and he was kissing her ardently.

But after a moment he released himself gently.

"You haven't told me, dear," he said, "what you are doing here."

His voice held a note of authority before which Julia's assurance vanished.