"

"Well?"

"The commissioner asked me yesterday if I knew of a church in the city
that had a slender spire with a green top and two poplars in front of
it."

Muller looked his interest.

"I thought it might possibly be the Convent Church of the Grey Sisters,
but I wasn't quite sure, so I went there an hour ago. It's all right,
just as I thought. And I suppose it has something to do with the case of
last night, so I thought I had better report at once. I was on my way to
the station."

"That will do very well. You have saved us much time and you have shown
that you are eminently fitted for this business."

"If you really will try me, then--"

"We'll see. You can begin on this. Come to the church with me now."
Muller was no talker, particularly not when, as now, his brain was busy
on a problem.

The two men walked on quickly. In about half an hour they found
themselves in a little square in the middle of which stood an old
church. In front of the church, like giant sentinels, stood a pair of
tall poplars. One of them looked sickly and was a good deal shorter than
its neighbour. Muller nodded as if content.

"Is this the church the commissioner was talking about?" queried Amster.

"It is," was the answer. Muller walked on toward a little house built up
against the church, which was evidently the dwelling of the sexton.

The detective introduced himself to this official, who did not look
over-intelligent, as a stranger in the city who had been told that the
view from the tower of the church was particularly interesting. A bright
silver piece banished all distrust from the soul of the worthy man. With
great friendliness he inquired when the gentlemen would like to ascend
the tower. "At once," was the answer.

The sexton took a bunch of keys and told the strangers to follow him. A
few moments later Muller and his companion stood in the tiny belfry room
of the slender spire. The fat sexton, to his own great satisfaction,
had yielded to their request not to undertake the steep ascent. The
cloudless sky lay crystal clear over the still sleeping city and the
wide spread snow-covered fields which lay close at hand, beyond the
church. On the one side were gardens and the low rambling buildings
of the convent, and on the other were huddled high-piled dwellings of
poverty.

Muller looked out of each of the four windows in turn. He spent some
time at each window, but evidently without discovering what he looked
for,