Both torches flared up.
The problem was now to discover the way by which the ghost had disappeared.

Roland and Sir John lowered their torches and examined the ground.

The cistern was paved with large squares of limestone, which seemed to fit perfectly.

Roland looked for his second ball as persistently as for the first.

A stone lay loose at his feet, and, pushing it aside, he disclosed an iron ring screwed into one of the limestone blocks.
Without a word Roland seized the ring, braced his feet and pulled.
The square turned on its pivot with an ease which proved that it was frequently subjected to the same manipulation.