ate. A little way beyond the gate was a small
barn or outhouse.

"We are in luck," Thorndyke remarked, with a glance at the path.
"Yesterday's rain has cleared away all old footprints, and prepared the
surface for new ones. You see there are three sets of excellent
impressions--two leading away from the house, and one set towards it.
Now, you notice that both of the sets leading _from_ the house are
characterized by deep impressions and short steps, while the set leading
_to_ the house has lighter impressions and longer steps. The obvious
inference is that he went down the path with a heavy burden, came back
empty-handed, and went down again--and finally--with another heavy
burden. You observe, too, that he walked with his stick on each
occasion."

By this time we had reached the bottom of the garden. Opening the gate,
we followed the tracks towards the outhouse, which stood beside a
cart-track; but as we came round the corner we both stopped short and
looked at one another. On the soft earth were the very distinct
impressions of the tyres of a motor-car leading from the wide door of
the outhouse. Finding that the door was unfastened, Thorndyke opened it,
and looked in, to satisfy himself that the place was empty. Then he fell
to studying the tracks.

"The course of events is pretty plain," he observed. "First the fellow
brought down his luggage, started the engine, and got the car out--you
can see where it stood, both by the little pool of oil, and by the
widening and blurring of the wheel-tracks from the vibration of the free
engine; then he went back and fetched the boy--carried him pick-a-back,
I should say, judging by the depth of the toe-marks in the last set of
footprints. That was a tactical mistake. He should have taken the boy
straight into the shed."

He pointed as he spoke to one of the footprints beside the wheel-tracks,
from the toe of which projected a small segment of the print of a little
rubber heel.

We now made our way back to the house, where we found Willett pensively
rapping at the front door with a cycle-spanner. Thorndyke took a last
glance, with his hand in his pocket, at an open window above, and then,
to the coachman's intense delight, brought forth what looked uncommonly
like a small bunch of skeleton keys. One of these he inserted into the
keyhole, and as he gave it a turn, the lock clicked, and the door stood
open.

The little sitting-room, which we now entered, was furnished with