tly through the
thick coating of distemper which had been applied. He damped a
handkerchief with his tongue and rubbed away some of the whitewash
where the letters were least legible and read:

AID
LTER.
------
ULANCE &
T AID.

This was evidently half an inscription which had been cut off exactly in
the middle. To the left there was no sign of lettering. He puzzled the
letters for a few moments before he came to an understanding.

"Air-raid shelter. Ambulance and first aid!" he read.

So that explained the new electric fittings. It was one of those
underground cellars which had been ferreted out by the Municipality or
the Government for the shelter of the people in the neighbourhood during
air-raids in the Great War. Evidently there was extensive accommodation
here, since this was also an ambulance post. Faintly discernible beneath
the letters was a painted white hand which pointed downward. What had
happened to the other half of the inscription? Obviously it had been
painted on the door leading into the first-aid room and as obviously
that door had been removed and had been bricked up. In the light of this
discovery he made a more careful inspection of the wall to the left. For
the space of four feet the brickwork was new. He tapped it. It sounded
hollow. Pressing his back against the opposite wall to give him leverage
he put his foot against the new brickwork and pushed.

He knew that the class of workmanship which was put into this kind of
job was not of the best, that only one layer of brick was applied, and
it was a mechanical fact that pressure applied to the centre of new work
would produce a collapse.

At the first push he felt the wall sag. Releasing his pressure it came
back. This time he put both feet against the wall and bracing his
shoulders he put every ounce of strength in his body into a mighty
heave. The next second he was lying on his back. The greater part of the
wall had collapsed. He was curious enough to examine the work he had
demolished. It had evidently been done by amateurs, and the whitewash
which had been thickly applied to the passage was explained.

A current of fresh air came to meet him as he stepped gingerly across
the debris. A flight of six stone steps led down to a small room
containing a sink and a water supply, t