e advertisement has not already been given in, can you give a
note to whoever brings it?" she asked, in a flash of inspiration.

"Yes, that could be done." She tore off her glove, and with slim,
nervous fingers wrote hurriedly. The sleek clerk supplied her with an
envelope, and as she placed her message in it and handed it to him she
felt it was a forlorn hope. There was only one other way of outwitting
the detectives. Should Grell give any address in his message, she must
reach him early in the morning before the police could act. A couple of
questions elicited the fact that the paper would be on sale by four the
next morning. That would mean another journey to Fleet Street, for the
ordinary news-agents' shops would not be open at that time. The brougham
turned about and began the homeward journey.

A respectably dressed working man, who had apparently been absorbed in a
page of advertisements of situations vacant displayed on a slab in the
window, slouched into the office, and a man bareheaded and wearing a
frock-coat moved briskly forward, apparently to attend to him. Yet it
was more than coincidence that they met at a deserted end of the
counter.

"That was Lady Eileen Meredith," said the workman, in a quick, low
voice. "What did she want?"

"She's guessed that we know the cipher," retorted the other. "She gave a
letter to be handed over to whoever brings the advertisement. Here is
what she says." He pulled the letter which Eileen had written five
minutes before from its envelope: "'The police know the cipher. Be very
cautious. R. F. is acting with them.' I'll telephone to Mr. Foyle at
once. You had better stay outside."

The second man went back to the pavement and resumed his study of the
advertisement board, but a close observer might have seen that his eyes
wandered past it now and again to the persons inside the office. Half an
hour went by. Then the frock-coated man inside took a silk hat from a
peg and placed it on his head. Simultaneously a woman went out. A dozen
paces behind her went the workman, and a dozen paces behind him the
frock-coated man.

Heldon Foyle had selected his subordinates well for their work. Acting
on the policy of leaving nothing to chance, he had taken a hint from the
advertisement addressed to Eileen, and had the office watched from the
time it opened. It was simple to get the manager's permission to place
one man within, and to get him to direct the clerks to pass through his