I think about ten minutes passed when I heard the whir of a motor-car approaching, its big glaring headlamps shedding a stream of white brilliance over the muddy road. As it approached her it slowed down and stopped. Then I distinguished it to be a big Limousine, the occupant of which opened the door, and she entered with a word of greeting. I stood peering into the darkness, in surprise and disappointment at not catching sight of the person with whom she was keeping these nightly appointments. As soon as the door had banged the driver drove across the road, backed, and turning, sped away in the direction he had come. But while he was turning I had gained the road, advancing beneath the hedgerow in an endeavour to see the number of the car. But I was baffled. It was covered with mud. Afterwards, much disappointed, and certainly hungry, I made my way back across the park to the Hall, where, after managing to get a snack from Williams, I joined the party at bridge. That night the woman Stolberg returned at five minutes to eleven, and later, when Ray went upstairs with me, I described what I had seen. Next night, instead of following her out, I waited at the spot at half-past ten, when, sure enough, the car returned ten minutes later and deposited her. The number plates, however, were obliterated by the mud both front and back--purposely it seemed to me. The man within shook her hand as she alighted, but I could not see his face. Was he some secret lover? Apparently she went no great distance each evening, going and coming from the direction of Holt. On the following day I took several opportunities of watching the woman at close quarters. Her eyes were peculiarly set, very close together, her lips were thin, and her cheek-bones rather high. Otherwise she was not bad-looking. Mrs. Hill-Mason had, of course, no idea of her maid's nocturnal motor-rides. Whether the woman had any suspicion that she was being watched I know not; but on the next night when Ray took a turn at keeping an eye upon her, she did not go out, but on the next she went, and Ray followed her to the park wall, but saw nothing more than I had done. All this time, of course, Vera was greatly interested in the result of our observations. Through her own maid, Batson, she discovered the room occupied by the German, and to this I made my way, at considerable risk, one morning while the maid was busy attending upon her mistress. I had a good look through her belongings, finding in her trunk a small, flat tin box, japanned dark green, strong, and secured by a lock of well-known make. What, I wondered, did it contain? Could I have but seen the number of the mysterious car I could have discovered the identity of her nocturnal visitor. The same day that I discovered the tin box in her trunk, Mrs. Hill-Mason, however, returned to London, taking with her the mysterious Fräulein.