mber. Mark has kept this a secret for a year. Could he have kept
it a secret in the dining-room? Could Miss Norris have got into the
dining-room and used the secret door just after dinner without being
seen? It would have been much too risky."

Bill got up eagerly.

"Come along," he said, "let's try the library. If Cayley comes in, we
can always pretend we're choosing a book."

Antony got up slowly, took his arm and walked back to the house with
him.

The library was worth going into, passages or no passages. Antony could
never resist another person's bookshelves. As soon as he went into the
room, he found himself wandering round it to see what books the owner
read, or (more likely) did not read, but kept for the air which they
lent to the house. Mark had prided himself on his library. It was a
mixed collection of books. Books which he had inherited both from his
father and from his patron; books which he had bought because he was
interested in them or, if not in them, in the authors to whom he wished
to lend his patronage; books which he had ordered in beautifully bound
editions, partly because they looked well on his shelves, lending a
noble colour to his rooms, partly because no man of culture should ever
be without them; old editions, new editions, expensive books, cheap
books, a library in which everybody, whatever his taste, could be sure
of finding something to suit him.

"And which is your particular fancy, Bill?" said Antony, looking from
one shelf to another. "Or are you always playing billiards?"

"I have a look at 'Badminton' sometimes," said Bill.

"It's over in that corner there." He waved a hand.

"Over here?" said Antony, going to it.

"Yes." He corrected himself suddenly.--"Oh, no, it's not. It's over
there on the right now. Mark had a grand re-arrangement of his library
about a year ago. It took him more than a week, he told us. He's got
such a frightful lot, hasn't he?"

"Now that's very interesting," said Antony, and he sat down and filled
his pipe again.

There was indeed a "frightful lot" of books. The four walls of the
library were plastered with them from floor to ceiling, save only where
the door and the two windows insisted on living their own life, even
though an illiterate one. To Bill it seemed the most hopeless room of
any in which to look for a secret opening.

"We shall have to take every blessed book down," he said, "before we can
be certain that we haven't missed it."