t was beginning to grow dark, almost too dark for landing. But now Jim could feel the tang of the salt wind upon his face. He slowed down. The fog was as thick as ever, but the scrub oak had given place to more open country. In a minute or two he ought to sight some landmark. Yes, he had overshot his mark, for suddenly, through a gap in the mists, he saw the line of breakers forming a white ridge upon the sand.
A mile southward! Jim knew where he was now, for he knew every curve of that shore. He banked and turned. And then he saw something that for an instant chilled his blood.
Not far away, and not far beneath him, a ghostly violet haze was spreading through the fog, and the fog itself was coiling back from it until it formed a dense white wall.
For a moment Jim's hand was paralysed upon the stick. The next, his decision was made. He closed his throttle and went down in a slow descent right toward the heart of that column of lavender smoke that seemed to be springing straight up out of the ground. "A pillar of violet fire!" It could not have been described better.
The plane dived through the dense wall of fog, which for a moment shut out the violet fire completely. Then Jim was through, and almost immediately beneath him lay the black and glassy surface of the pool. Out of the very heart of it rose the fire, burning like some infernal flame that consumed nothing, and between it and the fog was a space of almost translucent air, extending to the borders of the pool.
Jim began to circle the pool to find a landing-place. But as he looked down, the surface of the pool began to change its aspect.
n place of the unruffled calm, it began to work with some devil's yeast all around the central pillar of flame, until its depths seemed to be churned up in frothy masses and the movement extended almost to the circumference. Then the whole surface of the water began to tilt and sway with a slow, shimmering, undulatory movement, as if it was a giant roulette wheel in rotation.
And something was materializing out of the heart of the violet flame itself.