ces
where it has passed across and obliterated the more shallow mark of the
front one. It was undoubtedly heading away from the school. It may or
may not be connected with our inquiry, but we will follow it backwards
before we go any farther."

We did so, and at the end of a few hundred yards lost the tracks as
we emerged from the boggy portion of the moor. Following the path
backwards, we picked out another spot, where a spring trickled across
it. Here, once again, was the mark of the bicycle, though nearly
obliterated by the hoofs of cows. After that there was no sign, but
the path ran right on into Ragged Shaw, the wood which backed on to the
school. From this wood the cycle must have emerged. Holmes sat down on
a boulder and rested his chin in his hands. I had smoked two cigarettes
before he moved.

"Well, well," said he, at last. "It is, of course, possible that a
cunning man might change the tires of his bicycle in order to leave
unfamiliar tracks. A criminal who was capable of such a thought is a man
whom I should be proud to do business with. We will leave this question
undecided and hark back to our morass again, for we have left a good
deal unexplored."

We continued our systematic survey of the edge of the sodden portion
of the moor, and soon our perseverance was gloriously rewarded. Right
across the lower part of the bog lay a miry path. Holmes gave a cry
of delight as he approached it. An impression like a fine bundle of
telegraph wires ran down the centre of it. It was the Palmer tires.

"Here is Herr Heidegger, sure enough!" cried Holmes, exultantly. "My
reasoning seems to have been pretty sound, Watson."

"I congratulate you."

"But we have a long way still to go. Kindly walk clear of the path. Now
let us follow the trail. I fear that it will not lead very far."

We found, however, as we advanced that this portion of the moor is
intersected with soft patches, and, though we frequently lost sight of
the track, we always succeeded in picking it up once more.

"Do you observe," said Holmes, "that the rider is now undoubtedly
forcing the pace? There can be no doubt of it. Look at this impression,
where you get both tires clear. The one is as deep as the other.
That can only mean that the rider is throwing his weight on to the
handle-bar, as a man does when he is sprinting. By Jove! he has had a
fall."

There was a broad, irregular smudge covering some yards of the track.
Then there were a few foo