"You do me too much honour," said Holmes, gravely.
"Let us hear how you arrived at this most gratifying result."

The detective seated himself in the arm-chair, and puffed
complacently at his cigar. Then suddenly he slapped his
thigh in a paroxysm of amusement.

"The fun of it is," he cried, "that that fool Lestrade,
who thinks himself so smart, has gone off upon the wrong track
altogether. He is after the secretary Stangerson, who had no
more to do with the crime than the babe unborn. I have no
doubt that he has caught him by this time."

The idea tickled Gregson so much that he laughed until he choked.

"And how did you get your clue?"

"Ah, I'll tell you all about it. Of course, Doctor Watson,
this is strictly between ourselves. The first difficulty
which we had to contend with was the finding of this
American's antecedents. Some people would have waited until
their advertisements were answered, or until parties came
forward and volunteered information. That is not Tobias
Gregson's way of going to work. You remember the hat beside
the dead man?"

"Yes," said Holmes; "by John Underwood and Sons, 129,
Camberwell Road."