"There's opium in the case, isn't there?" said Dunbar, adding more water
to his whisky, "and where there's opium there is pretty frequently a
Chinaman."

"But to my mind," persisted Sowerby, his eyebrows drawn together in a
frown of concentration, "the place where Mrs. Vernon used to get the
opium was the place we raided in Gillingham Street."

"Nurse Proctor's!" cried Stringer, banging his fist on the table.
"Exactly my idea! There may have been a Chinaman concerned in the
management of the Gillingham Street stunt, or there may not, but I'll
swear that was where the opium was supplied. In fact I don't think that
there's any doubt about it. Medical evidence (opinions differed a bit,
certainly) went to show that she had been addicted to opium for some
years. Other evidence--you got it yourself, Inspector--went to show that
she came from Gillingham Street on the night of the murder. Gillingham
Street crowd vanished like a beautiful dream before we had time to
nab them! What more do you want? What are we up to, messing about in
Limehouse and Wapping?"

Sowerby partook of a long drink and turned his eyes upon Dunbar,
awaiting the inspector's reply.

"You both have the wrong idea!" said Dunbar, deliberately; "you are
all wrong! You seem to be under the impression that if we could lay our
hands upon the missing staff of the so-called Nursing Home, we should
find the assassin to be one of the crowd. It doesn't follow at all.
For a long time, you, Sowerby,"--he turned his tawny eyes upon the
sergeant--"had the idea that Soames was the murderer, and I'm not sure
that you have got rid of it yet! You, Stringer, appear to think that
Nurse Proctor is responsible. Upon my word, you are a hopeless pair!
Suppose Soames had nothing whatever to do with the matter, but merely
realized that he could not prove an alibi? Wouldn't YOU bolt? I put it
to you."

Sowerby stared hard, and Stringer scratched his chin, reflectively.

"The same reasoning applies to the Gillingham Street people," continued
Dunbar. "We haven't the slightest idea of THEIR whereabouts because we
don't even know who they were; but we do know something about Soames,
and we're looking for him, not because we think he did the murder, but
because we think he can tell us who did."

"Which brings us back to the old point," interrupted Stringer, softly
beating his fist upon the table at every word; "why are we looking for
Soames in the east-end?"

"Because," replied