ten o'clock
The Prince left his own apartments , and hurried down a private staircase and through dark passages to the door designated . It was only on latch , but a key was in the lock . Quickly he locked the door , and then stood listening intently . It struck ten o'clock , and as the last stroke vibrated in his ear a hand was laid upon the door latch outside , and a manly voice whispered : `` Trude , open ! It is I . The one whom you expect ! Open , quick ! ''