placid face an alert brain was working. Had the man
followed her, or was it a mere coincidence? Was he a detective? With an
effort of will she stilled the apprehension in her breast. Her
confidence reasserted itself. Even if he were a detective, what had she
to fear? She had merely delivered a cipher advertisement over the
counter. It was unlikely that it would be read by others than the
person for whom it was intended. Even if it were, there was nothing in
it to incriminate her.

Her lips parted in a contemptuous smile.

"I don't believe he is a detective at all," she murmured.

All doubts on the subject, however, were set at rest as the express
began to glide out of the station. As though taken unawares by its
departure, the man hastily shook hands with his friend and sprinted for
the train, swinging himself into the woman's compartment with a gasp of
relief.

"Phew," he said. "A narrow shave that," and then, as if realising the
sex of his companion, "I--I beg your pardon. I hope the carriage is not
reserved. If so, I will change."

She smiled winningly at him.

"No, don't disturb yourself, I beg. It would be a pity after all the
trouble you have taken--to catch the train."

Detective-Inspector Blake was not by any means dull. His immobile
features gave no sign that he was half inclined to believe the woman was
gibing him. "Now, what the devil does she mean by that?" he said, under
his breath. He bowed in acknowledgment of her courtesy, and drawing a
paper from his pocket unfolded it.

"And how is the charming Mr. Foyle?" said the Princess, speaking with a
soft drawl. "I do hope he is still well."

This time Blake was taken unawares. He dropped the paper as though it
were red-hot, and the woman laughed. A moment later he was ashamed of
himself. She had trapped him into a tacit admission that he was a
detective. A surprised denial of acquaintance with Mr. Foyle might have
ended in an apology on her part for a mistake. Well, it was too late
now.

"So you are a colleague of Mr. Foyle's?" she went on, and though her
voice was soft there was a trace of mockery in it. "He is charmingly
considerate to send you to look after me. I was desolated to think that
I should have to take such a long journey by myself."

"The pleasure is mine," said Blake, falling in quickly with the
atmosphere she had set. Nevertheless, he was not quite easy. He recalled
the troubles that had beset Waverley, and half regretted that he h