In choosing a few typical cases which illustrate the remarkable mental
qualities of my friend, Sherlock Holmes, I have endeavoured, as far as
possible, to select those which presented the minimum of sensationalism,
while offering a fair field for his talents. It is, however, unfortunately
impossible entirely to separate the sensational from the criminal, and a
chronicler is left in the dilemma that he must either sacrifice details which
are essential to his statement and so give a false impression of the problem,
or he must use matter which chance, and not choice, has provided him
with. With this short preface I shall turn to my notes of what proved to
be a strange, though a peculiarly terrible, chain of events.