Then a wild shout of surprise broke from the lips of all of them, followed by a moment of stupefied wonder.

The whole staircase suddenly began to revolve.

Craig, clinging to the banisters, disappeared.

In a moment or two there was a fresh click.
Another set of stairs, almost identical to the first, had taken their place.
"The cellar!" Quest shouted, as he rushed down the stairs.

"Quick!" They wrenched open the wooden door and hurried down the dark steps into the gloomy, unlit cellar.