"Ah, I thought we should see you here before long, doctor," said he
genially. "I heard this morning that you have this thumb-print case in
hand."

"Yes," replied Thorndyke; "I am going to see what can be done for the
defence."

"Well," said the officer as he ushered us into the building, "you've
given us a good many surprises, but you'll give us a bigger one if you
can make anything of this. It's a foregone conclusion, I should say."

"My dear fellow," said Thorndyke, "there is no such thing. You mean that
there is a _prima facie_ case against the accused."

"Put it that way if you like," replied the officer, with a sly smile,
"but I think you will find this about the hardest nut you ever tried
your teeth on--and they're pretty strong teeth too, I'll say that. You
had better come into Mr. Singleton's office," and he conducted us along
a corridor and into a large, barely-furnished room, where we found a
sedate-looking gentleman seated at a large writing table.

"How-d'ye-do, doctor?" said the latter, rising and holding out his hand.
"I can guess what you've come for. Want to see that thumb-print, eh?"

"Quite right," answered Thorndyke, and then, having introduced me, he
continued: "We were partners in the last game, but we are on opposite
sides of the board this time."

"Yes," agreed Mr. Singleton; "and we are going to give you check-mate."