She rose and walked to the fireplace, her elbows on the mantelpiece, and
her head back.

"I'll tell you all I can. Perhaps you're right," she said. "There has
been too much mystery. You asked me once who was Milburgh."

She turned and half-faced him.

"I won't ask you that question any more," he said quietly, "I know!"

"You know?"

"Yes, Milburgh is your mother's second husband."

Her eyes opened.

"How did you find out that?"

"I guessed that," he smiled, "and she keeps her name Rider at Milburgh's
request. He asked her not to reveal the fact that she was married again.
Isn't that so?"

She nodded.

"Mother met him about seven years ago. We were at Harrogate at the time.
You see, mother had a little money, and I think Mr. Milburgh thought it
was much more than it actually was. He was a very agreeable man and told
mother that he had a big business in the city. Mother believes that he is
very well off."

Tarling whistled.

"I see," he said. "Milburgh has been robbing his employers and spending
the money on your mother."

She shook her head.

"That is partly true and partly untrue," she said. "Mother has been an
innocent participant. He bought this house at Hertford and furnished it
lavishly, he kept two cars until a year ago, when I made him give them up
and live more simply. You don't know what these years have meant, Mr.
Tarling, since I discovered how deeply mother would be dragged down by
the exposure of his villainy."

"How did you find it out?"

"It was soon after the marriage," said the girl. "I went into Lyne's
Store one day and one of the employees was rude to me. I shouldn't have
taken much notice, but an officious shop-walker dismissed the girl on the
spot, and when I pleaded for her reinstatement, he insisted that I should
see the manager. I was ushered into a private office, and there I saw Mr.
Milburgh and realised the kind of double life he was living. He made me
keep his secret, painted a dreadful picture of what would happen, and
said he could put everything right if I would come into the business and
help him. He told me he had large investments which were bringing in big
sums and that he would apply this money to making good his defalcations.
That was why I went into Lyne's Store, but he broke his word from the
very beginning."

"Why did he put you there?" asked Tarling.

"Because, if there had been another person," said the girl, "he might
have been detected. He knew that any