lay, and
very carefully shut it away in a wide drawer where no draught could
disturb it; he also shut another drawer which stood open.

"We had no difficulty in finding Dr. Lawson," Plummer began. "We met
him, in fact, leaving his surgery. I went back with him into the
gas-light, and there put it to him plump. Well, he was staggered, badly.
Any man would be, of course. But he pulled himself together wonderfully
soon, and the first thing he said was that he was just on his way to
Mason's house. I thought at first, of course, that he meant to deny that
he had been there already, and I gave him the usual warning about what
he said being used in evidence. But he went on, and I've got it all
safely noted. He admitted that he had been here, at about seven o'clock
or just before, and he said he came because Mr. Mason sent for him. That
doesn't seem likely, does it, on the facts as we know them?"

"Why, no," said the rector. "The last time he was here he was ordered
out, and I know of no reason why he should have been asked to come
to-day. We must ask if anybody was sent."

"I have asked," replied Plummer, "just now, and none of the servants was
sent. But Lawson's story is that he _was_ sent for and came, though he
said he shouldn't say what Mason wanted to see him about till he knew
more of the case. Looks as though he hadn't quite got his story ready
yet, doesn't it? He had thought over the point about not being seen to
go away, though; he said he had let himself out at about half-past
seven, being familiar with the ways of the house. And he said that Mason
was rather unwell--nervously upset--when he left him, but that was
all."

"It's terrible," said the rector, "terrible. It seems impossible to
believe it of young Lawson; and yet--and yet!" And then after a
pause--"Good heavens!" he burst out again. "Why, I only realise it now!
There is the other crime, too! Denson! Two murders! Two--and most
certainly by the same hand! Mr. Plummer, I _can't_ believe it! Oh,
there's more behind, more behind, Mr. Hewitt."

"There _is_ more," said Hewitt, "as you will see when I tell you the
little I have been able to ascertain. There _is_ more behind, though I
see little of it yet. First----"

There was a sharp knock at the front door, followed by a ring, muffled
in the distant kitchen. Hewitt started up. "Who is this late visitor at
this unvisited house?" he said. "If it is the police, well enough. But
if anybody else--_anybody_--yo