at breaking in a door, and, like all the criminal groups that we
get without an invitation from over the Channel, these crooks
have absolutely no regard for human life.'

"That's the way Sir Henry led off with his explanation. Of
course he had all that Scotland Yard knew about criminal groups
to start him right. It was a good deal to have the identity of
the criminal agents selected out; but I didn't see how he was
going to manage to explain the mystery from the evidence. I was
wild to hear him. Mr. Meadows was quite as interested, I
thought, although he didn't say a word.

"Sir Henry nodded, as though he took the American's confirmation
as a thing that followed. `We are at the scene,' he said, `of
one of the most treacherous acts of all criminal drama. I mean
the "doing in," as our criminals call it, of the unprofessional
accomplice. It's a regulation piece of business with the
hard-and-fast criminal organizations of the Continent, like the
Nervi of Marseilles, or the Lecca of Paris.

"`They take in a house servant, a shopkeeper's watchman, or a
bank guard to help them in some big haul. Then they lure him
into some abandoned house, under a pretense of dividing up the
booty, and there put him out of the way. That's what's happened
here. It's a common plan with these criminal groups, and clever
of them. The picked-up accomplice would be sure to let the thing
out. For safety the professionals must "do him in" at once,
straight away after the big job, as a part of what the barrister
chaps call the res gestae.'