along a new track.

"I am informed," he went on, speaking with a deliberateness meant to
be impressive, "that you did entertain another lady as a visitor
last night."

Grant allowed his glance to dwell on Robinson for an instant. Hitherto he
had ignored the man. Now he surveyed him as if he were a viper.

"It will be a peculiarly offensive thing if the personality of a helpless
and unoffending girl is brought into this inquiry," he cried. "'Brought
in' is too mild--I ought to say 'dragged in.' As it happens, astronomy is
one of my hobbies. Last evening, as the outcome of a chat on the subject,
Doris Martin, daughter of the local postmaster, came here to view Sirius
through an astronomical telescope. There is the instrument," and he
pointed through P.C. Robinson to a telescope on a tripod in a corner of
the room. The gesture was eloquent. The burly policeman might have been a
sheet of glass. "As you see, it is a solid article, not easily lifted
about. It weighs nearly a hundred-weight."

"Why is it so heavy?"

The superintendent had a knack of putting seemingly irrelevant questions.
Robinson had been disconcerted by it earlier in the day, but Grant seemed
to treat the interruption as a sensible one.

"For observation purposes an astronomical telescope is not of much use
unless the movement of the earth is counteracted," he said. "Usually, the
dome of an observatory swings on a specially contrived axis, but that is
a very expensive structure, so my telescope is governed by a clockwork
attachment and moves on its own axis."

Mr. Fowler nodded. He was really a very well informed man for a country
police-officer; he understood clearly.

"Miss Martin came here about a quarter to ten," continued Grant, "and
left within three-quarters of an hour. She did not enter the house. She
was watching Sirius while I explained the methods whereby the distance of
any star from the earth is computed and its chemical analysis
determined--"

"Most instructive, I'm sure," put in the superintendent.

He smiled genially, so genially that Grant dismissed the notion that the
other might, in vulgar parlance, be pulling his leg.

"Well, that is the be-all and end-all of Miss Martin's presence. It would
be cruel, and unfair, if a girl of her age were forced into a distasteful
prominence in connection with a crime with which she is no more related
than with Sirius itself."

The older man shook his head in regretful dissent.

"That is