urning to Lorraine: "I suppose you're at home to-day if I chance to
want you?"

"You'll find me at school at The Gables until four o'clock."

He nodded, and made another entry in his notebook, then, dismissing
them courteously, rang up his chief on the telephone.

Lorraine went home to breakfast, feeling as if she had suddenly stepped
into the pages of a detective story. That some treachery was taking
place at Porthkeverne was beyond question: loyal subjects of King George
do not supply U-boats with casks of oil, and the man whom she had seen
was palpably no British subject, but a foreigner. She wondered what the
next step in the course of events would be, and what help she would be
able to render. The answer to her surmisings came from a direction she
had not anticipated. She had only been at school about an hour, and was
at work on a piece of unseen Latin translation, when a message was
brought to her summoning her to the study. She found her Uncle Barton
there, talking to Miss Janet.

"Lorraine," he said briefly, "Miss Kingsley has excused your lessons
to-day. Get your hat and coat and come with me, for I want to take you
by train. We've just time to catch the 10.40 if we're quick."

Much excited and puzzled, Lorraine flew to the cloak-room, and donned
her outdoor shoes and hat with lightning speed. What was going to happen
next in this amazing chain of events? On the way to the station, Uncle
Barton explained.

"The police have long been trying to catch a notorious spy, and from
the description you gave this morning, they think they are on the right
track of the man they want. A certain foreigner at St. Cyr is under
observation, but they cannot arrest him without a witness to his
identity. If you can certify that to the best of your knowledge he is
the man whom you saw this morning supplying casks of oil to a U-boat,
then the police can act. Should you know him again if you saw him?"

"I'd remember him anywhere now!" declared Lorraine.

It was a comparatively short journey to St. Cyr, and on arrival there
they went straight to the police station. They were shown by a constable
into a private office, where they were shortly joined by a detective. He
questioned Lorraine carefully as to the various occasions on which she
had seen the suspected foreigner.

"A man answering exactly to that description has been staying at a
boarding-house in Spring Terrace," he commented. "We happen to know that
he was out all l