stuck in the fork of a tree, beside it, was a weathered
old piece of ship's planking on which had been rudely cut the single
word WATTER.

"Some Captain who used to fill his casks here must have put it up so
that the spring would be easier to find," Bob suggested. But Jeremy,
striding ahead, was thinking hard and did not answer.

Amos Swan heard their news with a grave face. No ship but the _Queen_
had touched at the island for several months to his knowledge, he said.
He agreed with the boys that the secrecy of the thing looked suspicious.
When Tom came in for the noon meal, his father told him of the discovery
and they both decided to bring the sheep in at once, and make
preparations for possible trouble.

Tom, armed, and accompanied by the boys, set out soon after dinner for
the western end of the island, two miles from the shack. It was there
that the flock was accustomed to graze, shepherded by the wise dog,
Jock. Their way led along the rocky northern slope, where the sheep had
already worn well-defined paths among the scrubby grass and juniper
patches, then up across a steep knoll and through a belt of fir and
hemlock. When at length they came out from among the trees, the pasture
lay before them. There in a hollow a hundred yards away the flock was
huddled. Jock became aware of their approach at that instant and lifted
his head in a short, choking bark. He started toward them, but before he
had taken a dozen steps they could see that he was limping painfully.
Running forward, Jeremy knelt beside the big collie, then turned with a
movement of sudden dismay and called to his comrades. He had seen the
broad splotch of vivid red stained the dog's white breast. Examination
showed a deep clean cut in the fur of the neck, from which the blood
still flowed sluggishly. But in spite of his weakness and the pain he
evidently suffered, Jock could hardly wait to lead his masters back to
the flock. Hurrying on with him they crossed a little rise of ground and
came upon the sheep which were crowded close to one another, panting in
abject terror.

[Illustration: Jock]

"Twenty-six--twenty-eight--yes, twenty-eight and that's all!" Tom said.
"There are two of them missing!"

Jock had limped on some twenty yards further and now stood beside a
juniper bush, shivering with eagerness.

Following him thither, the boys found him sniffing at a blood-soaked
patch of grass. The ground for several feet around was cut up as if in