journey to town Caldegard and Randal
Bellamy ate their hearts in silence. The road was good, and they had it
almost to themselves.

As they were nearing London, Caldegard spoke.

"Bellamy," he said, "that brother of yours won't stop at killing if----"

"He'll begin with it," replied Randal, "if he gets a fair chance."

"It gives me unreasonable hope," said Caldegard.

"Men who've trusted Dick would call your hope reasonable."

"Yet he's sent us after Ambrotox," complained the father, "and my
heart's breaking for my little girl."

"His argument convinced you, anyhow," said Randal.

At New Scotland Yard Sir Randal's card gained them instant admission to
the presence of the Superintendent of the Criminal Investigation
Department.

He listened without a word to Randal's compact and lucid statement of
the facts.

"It's a good thing I was kept here so late to-night, gentlemen," he
said. "We shall act without losing a moment in the matter of your
daughter's disappearance, Dr. Caldegard. But the theft of your secret,
of which both Sir Charles Colombe and the Home Secretary have spoken to
me, is a matter of such tremendous importance, that I am obliged to
communicate immediately with both these gentlemen and the Commissioner.
And you will be doing me a great kindness if you will both remain here
until I hear from them."

An hour later a sombre group of six, after protracted discussion, seemed
almost to have exhausted the evidence, suggestion and counsel which
could be brought to bear upon a crime so sudden and so obscure.

Sir Charles Colombe looked anxiously round him as he spoke.

"That is the danger," he said, "which we have to face: that these foul
pests of society should escape with Professor Caldegard's discovery and
master his secret--a peril to which all the dangers mankind has run
since the world began from greed, bigotry, alcohol and opium are child's
play. The bill of which Sir Gregory has just spoken would give us powers
to lay hands on all these local branches of what Superintendent Finucane
has described as 'the Dope Gang.' We know already some twenty-five or
thirty of them. If we were as well advanced in our knowledge of their
central organisation, we might even now do something fairly vigorous
under the law of conspiracy. As it is, we can only proceed against
individuals trafficking in and supplying certain specified drugs. The
secret of this greatest drug of all must not, if human power can preven