A wolf will do this, and no more, in broad day.

At night he might follow, and others would join him in the chase; but with daylight about him he gives the warning and after a little slinks away from the trail.
But something held this wolf.

There was a mystery in the air which puzzled him.

Straight ahead there ran the broad, smooth trail of a sled and the footprints of many dogs.

Sometime within the last hour the "dog mail" from Wabinosh House had passed that way on its long trip to civilization.