above us!

"Damn my thick head!" roared Bristol, furiously. "He's on the roof!
It's flat as a floor and there's enough ivy alongside the water-spout
on your house adjoining, Mr. Mostyn, to afford foothold to an
invading army!"

He plunged off toward the open door, and I heard him racing down
the Assyrian Room.

"He had a short rope ladder fixed from the gutter!" he cried back
at us. "Graham! Graham!" (the constable on duty in the hall)--
"Get the front door open! Get . . . " His voice died away as he
leapt down the stairs.

From the direction of Orpington Square came a horrid, choking
scream. It rose hideously; it fell, rose again--and died.

The thief escaped. We saw the traces upon the ivy where he had
hastened down. Bristol ascended by the same route, and found where
the ladder-hooks had twice been attached to the gutterway. Constable
Graham, who was first actually to leave the building, declared that
he heard the whirr of a re-started motor lower down Great Orchard
Street.

Bristol's theory, later to be dreadfully substantiated, was that
the thief had broken the glass and reached into the case with an
arrangement similar to that employed for pruning trees, having a
clutch at the end, worked with a cord.