uptly and sprang to his feet.

"Good God!" he cried. "Suppose another one----"

On the bare floor beside the table they came upon a few drops of water.

"That must be it," said the Doctor. He pulled his handkerchief from his
pocket; then he stopped in thought. "No, that won't do. What shall we do
with it?" he added. "We must destroy it absolutely. Good Lord, if that
drug ever gets loose upon the world----"

The Big Business Man joined them.

"We must destroy it absolutely," repeated the Doctor. "We can't just
wipe it up."

"Some acid," suggested the Big Business Man.

"Suppose something else has got at it already," the Very Young Man said
in a scared voice, and began hastily looking around the floor of the
room.

"You're right," agreed the Doctor. "We mustn't take any chance; we must
look thoroughly."

Joined by the Banker, the four men began carefully going over the room.

"You'd better watch that nothing gets at it," the Very Young Man thought
suddenly to say. The Banker obediently sat down by the little pool of
water on the floor.

"And I'll close the window," added the Very Young Man; "something might
get out."

They searched the room thoroughly, carefully scanning its walls and
ceiling, but could see nothing out of the ordinary.

"We'll never be quite sure," said the Doctor finally, "but I guess we're
safe. It's the best we can do now, at any rate."

He joined the Banker by the table. "I'll get some nitric acid," he
added. "I don't know what else----"

"We'll have to get that out of here, too," said the Big Business Man,
pointing to the rug. "God knows how we'll explain it."

The Doctor picked up one of the tin boxes of drugs and held it in his
hand meditatively. Then he looked over towards the rug. From under one
side a brownish liquid was oozing; the Doctor shuddered.

"My friends," he said, holding up the box before them, "we can realize
now something of the terrible power we have created and imprisoned here.
We must guard it carefully, gentlemen, for if it escapes--it will
destroy the world."

CHAPTER XII

THE START

On the evening of November 4th, 1923, the four friends again assembled
at the Scientific Club for the start of their momentous adventure. The
Doctor was the last to arrive, and found the other three anxiously
awaiting him. He brought with him the valise containing the ring and a
suitcase with the drugs and equipment necessary for the journey. He
greeted his friend