If the police solve this
affair, that reward'll go to the police, and you'll get your proper
share. No--no underhand work. You make your report in your ordinary way.
No more of that!"

"Aye, but do you understand, Mr. Allerdyke?" said the detective
anxiously. "Do you comprehend what it'll mean. You know very well that
there's a lot of red tape in our work--they go a great deal by rule and
precedent, as you might say. Now, if I go to the Yard--as I shall have
to, as soon as you've done with me--and tell the chief that I've found
this photo of your cousin in Lydenberg's watch, and that you're certain
that your cousin gave that particular photo to Mrs. Marlow, alias Miss
Slade, do you know what'll happen?"

"What?" asked Allerdyke.

"They'll arrest her within half an hour," answered Chettle.
"Dead certain!"

"Well?" said Allerdyke. "And--what then!"

"Why, it'll probably upset the whole bag of tricks!" exclaimed Chettle.
"The thing'll be spoiled before we've properly worked it out. See?"

Allerdyke did see. He had sufficient knowledge of police matters to know
that Chettle was right, and that a too hasty step would probably ruin
everything. He turned towards the warehouse.

"Just so," he said. "I take your meaning. Now then, come in, and we'll
put it before my manager, Mr. Appleyard. I've great faith in his
judgment--let's see what he's got to say."

The two Gaffneys were waiting just within the packingroom of the
warehouse. Allerdyke bade them wait a little longer, and took the
detective straight into Appleyard's office. There, behind the closed
door, he told Appleyard of everything that had happened since their last
meeting, and of what Chettle had just said. The problem was, in view of
all that, of the mysterious proceedings of Mrs. Marlow the night before,
and of what Allerdyke had just heard at New Scotland Yard--what was best
to be done, severally and collectively, by all of them?

Ambler Appleyard grasped the situation at once and solved the problem in
a few direct words. There was no need whatever, he said, for Chettle to
do more than his plain duty, no need for him to exceed it. He was bound,
being what he was, to make his report about his discovery of the
photograph and the writing on it. That he must do. But he was not bound
to tell anything that Allerdyke had told him: he was not bound to give
information which Allerdyke had collected. Let Chettle go and tell the
plain facts about his own knowledge o