Dr. Hunter, under the auspices of a
Western university, had sailed with his instruments and assistants to
Davis Island, to study the solar corona during the few precious
moments when the shadow covered the sun, and to observe the
displacement of certain stars as a test of Einstein's theory of
relativity.

The reporter had interviewed the party at San Francisco, on the eve of
sailing. There had been photographs of the chartered vessel, of Dr.
Hunter and his instruments, and of his daughter, Helen, who acted as
his secretary. She looked not at all like a scientist, Dan recalled.
In fact, her face had seemed rather pretty, even in the blurred
newspaper half-tone.

But the memory cast no light upon the present puzzle. In the rambling
years that had led him to this spot upon the old _Virginia_, he had
lost touch with the science that had interested him during his college
days. He had heard nothing of the results of the Hunter expedition.
But this island had been its destination.

* * * * *

He turned decisively to the man at the wheel. "Larsen, we'll stand
well offshore till daylight," he said. "Then, unless we see something
unusual, we can sail in and land a boat to--"

The sentence was never finished. Through the corner of his eye, Dan
saw a ray of green light darting toward them from the island. A line
of green fire seemed to reach out and strike him a physical blow.
Green flame flared around him; and somehow he was hurled from the
bridge, clear of the rail and into the sea.

His impression of the incident was very confused. He seemed to have
struck the water with such force that his breath was knocked out. He
struggled back to the surface, strangling, and coughing the bitter
brine from his lungs. It was several minutes before he was comfortably
treading water, and able to see what had happened.

The old schooner was then a hundred yards away, careening crazily, and
drifting aimlessly before the light breeze. The strange green fire had
vanished. Parts of the ship apparently had been carried away or
disintegrated by the ray or the force of which it was a visible
effect. The mainmast was down, and was hanging over the side in a
tangle of rigging.

Bright yellow flames were dancing at a dozen points about the wreckage
on the listing deck. A grotesque broken thing, queerly illuminated by
the growing fires, was hanging over the wheel--the body of Larsen. No
living thing was visible; a