"Excuse me, but please--please--do not touch anything," said M.
Formery quickly.

"Why, this is odd," said the Duke, staring at the floor.

"What is odd?" said M. Formery.

"Well, this book looks as if it had been knocked off the table by
one of the burglars. And look here; here's a footprint under it--a
footprint on the carpet," said the Duke.

M. Formery and the inspector came quickly to the spot. There, where
the book had fallen, plainly imprinted on the carpet, was a white
footprint. M. Formery and the inspector stared at it.

"It looks like plaster. How did plaster get here?" said M. Formery,
frowning at it.

"Well, suppose the robbers came from the garden," said the Duke.

"Of course they came from the garden, your Grace. Where else should
they come from?" said M. Formery, with a touch of impatience in his
tone.

"Well, at the end of the garden they're building a house," said the
Duke.

"Of course, of course," said M. Formery, taking him up quickly. "The
burglars came here with their boots covered with plaster. They've
swept away all the other marks of their feet from the carpet; but