e sockets of the bolts, and that of the lock, have been loosened
from the inside with the poker," explained Malcolm Sage in a
matter-of-fact tone. "The marks upon the poker suggest a left-handed
man. The wound in the head proves it."

"Then the forced door was a blind?" gasped the inspector.

"The murderer was let in by the professor himself, who was
subsequently attacked from behind as he stood with his back to the
fireplace. You are sure the grate has not been touched?" He suddenly
raised his eyes in keen interrogation.

Inspector Carfon shook his head. He had not yet recovered from his
surprise.

"Someone has stirred the ashes about so as to break up the charred
leaves into small pieces to make identification impossible. This man
has a brain," he added.

The inspector gave vent to a prolonged whistle. "I knew there was
something funny about the whole business," he said as if in
self-defence.

Malcolm Sage had seated himself at the table, his long thin fingers
outspread before him. Suddenly he gave utterance to an exclamation
of annoyance.

The inspector bent eagerly forward.

"The pipe," he murmured. "I was wrong. He put it down because he was
absorbed in something, probably the papers he burnt."

"Then you think the murderer burnt the papers?" enquired the
inspector in surprise.

"Who else?" asked Malcolm Sage, rising. "Now we'll see the butler."

Whilst the inspector was locking and re-sealing the door, Malcolm
Sage walked round the building several times in widening circles,
examining the ground carefully; but there had been no rain for
several weeks, and nothing upon its surface suggested a footprint.

CHAPTER XII THE MARMALADE CLUE

I

AS Malcolm Sage and Inspector Carfon crossed the lawn from the
laboratory, Sir Jasper Chambers was seen coming down the drive
towards them.

"There's Sir Jasper," cried the inspector.

When they reached the point where the lawn joined the drive they
paused, waiting for Sir Jasper to approach. He walked with long,
loose strides, his head thrust forward, his mind evidently absorbed
and far away from where he was. His coat flapped behind him, and at
each step his trousers jerked upwards, displaying several inches of
grey worsted sock.

"Good afternoon, Sir Jasper," said Inspector Carfon, stepping
forward and lifting his hat.

Sir Jasper stopped dead, with the air of one who has suddenly been
brought to a realisation of his whereabouts. For