They were in the empty house at last. The windows were closed and
shuttered, so that it was possible to use matches in the various rooms
without attracting attention from the outside. But search how they would,
for upwards of two hours, they could find no trace whatever of a means of
communication between the two houses. They tapped the walls and sounded
the skirtings, but without success. Venner paced the floor of the
drawing-room moodily, racking his brains to discover a way out of the
difficulty.

"It must be here somewhere," he muttered. "I am sure all that
furniture was moved backwards and forwards through some door, and a
wide one at that."

"Then it must be on the ground floor," Gurdon remarked. "When you come to
think of it, some of that furniture was so heavy and massive that it
would not go through an ordinary doorway, neither could it have been
brought upstairs without the assistance of two or three men of great
strength. We shall have to look for it in the hall; if we don't find it
there, we shall have to give it up as a bad job and try some other plan."

"I am inclined to think you are right," Venner said. "Let us go down and
see. At any rate, there is one consolation. If we fail to-night we can
come again to-morrow."

Gurdon did not appear to be listening. He strode resolutely down the
stairs into the hall and stood for some moments contemplating the panels
before him. The panels were painted white; they were elaborately
ornamented with wreaths of flowers after the Adams' style of decoration.
Then it seemed to Gurdon that two pairs of panels, one above and one