Patricia knew that this was so, for above her in the foggy air rose the lofty pedestal of the Achilles statue. She must have wandered deviously across the vast space of the Park, and said so. The policeman readily accepted her explanation and added one of his own:

"I dessay you've got lost in the fog, miss, and no wonder, for it's as thick as pea-soup hereabouts. Not the night for a young lady to be out, miss," he ended inquisitively, and with a note of interrogation in his voice.

"I came out on an errand," said Miss Carrol faintly, for the adventure had left her weak, "and wandered off the Bayswater path near the Serpentine."

"And it's a mercy, miss, that you didn't fall in. What will you do now, miss?"

Patricia walked with him towards the gate, near the clock. "Call me a cab," she said, for although she could ill afford it, she decided to drive, as it was quite impossible to walk. The fog forbade pedestrianism, let alone that she was much too weary to trudge all the way to Crook Street.

"What; a cab, miss? Certainly, miss, although it will be hard to find one in this fog," and the constable whistled shrilly.

"What is the time, please?" Patricia asked the same question as she had put to the other policeman.

"Half-past eleven, miss."

The girl uttered a cry of astonishment, and well she might. Having left The Home of Art at half-past eight, she must have been wandering about for at least three hours. It seemed centuries, and she hastily made for the cab which drove slowly up, looking like a spectre in the fog. What would Mrs. Pentreddle think of her being absent for so long? But this question was nothing beside the one which the old lady was bound to ask with respect to the lost emerald. "Tell the man to drive to No. III, Crook Street, Bayswater," said Patricia feverishly, and bestowed herself in the hansom; "and here!"--she handed the kindly policeman one of her precious coins, which he accepted with a salute, and gave the necessary direction to the driver. In a few minutes Patricia was on her homeward way, thankful that her strange adventure had not cost her her life, as it might have done.

But her thoughts were extremely unpleasant. She had lost her umbrella, which she could ill afford to do; also the lantern of Mrs. Pentreddle, and, worst of all, the extraordinary jewel she had been sent to fetch. How could she explain? The only answer she could find was the very obvious one, that it would be best to tell the truth. Then she began to think what words she would use, until her head became confused and she dropped into an uneasy sleep. Meanwhile the cab crawled slowly and cautiously through the fog, towards The Home of Art. Patricia was made aware that she had arrived at her destination by the sudden jerk of the vehicle, as it came to a standstill. Then, still sleep-bemused, she alighted in a stumbling manner to find herself in the arms of Mrs. Sellars.