d employed him for nearly twenty years, and retire into private
life, like a harried mouse into its hole.

But that was only when he was at his very worst. Deep down within him he
was aware that, while the breath of life and his inscrutable genius were
together in him, he could not, would not, resign.

It was part of Ruthven Smith, an intimate part of him, not to be able
to decide for a long time what to do when he was confronted with one of
those emergencies unsuited to his temperament. He was afraid of doing
the wrong thing, yet was too reserved to consult any one. He generally
counted on blundering through somehow; and so it was in the matter of
the anonymous letter.

He had heard, and dimly believed, that it was morally wrong, and, still
worse, quite bad form, to take notice of anonymous letters. But this one
must be different, it seemed to him, from any other which anybody had
ever received. Duty to his employers and duty to the one thing he really
loved was above any other duty; and for fear of losing forever an
immense, an unhoped-for advantage, which might possibly be gained, he
dared not ignore the letter.

At all events, he had told himself, no matter what he might decide later,
it was just as well that he had accepted the invitation to Valley House.
Perhaps someone--he could not think who--was playing a stupid practical
joke, with the object of getting him there. But he would risk that and
go, and let his conduct shape itself according to developments.

For instance, if his eyes were able to detect the small detail
mysteriously mentioned in the letter, he would feel bound to act as it
suggested; yes, bound to act--but how unpleasant it would be!

And the worst of the whole unpalatable affair was that if he _did_ act in
that suggested way, and if he accomplished what he might, with dreadful
deftness, be supposed to accomplish, it would be the moment when perhaps
he might be fooled.

_If_ the letter were written by a practical joker, he would be made to
look ridiculous in the eyes of all who were in the secret. And that
thought brought him back to the question which over and over he asked
in his mind. Who could have written the anonymous letter?

It must be someone acquainted with him, or with his profession; someone
who knew the Nelson Smiths and the Annesley-Setons well enough to be
aware that there was to be an Easter party at Valley House. The writer
hinted in vague terms that he was a private detec