For an instant Jim Willis wondered uncomfortably if his leader had gone mad.  He had known sudden and apparently quite inexplicable cases of madness among sled-dogs, and, like most others having any considerable experience of the trail, he had more than once had to shoot a dog upon whom madness had fallen.  At all events, before striding forward to the head of his team Willis fumbled under the lashings of the sled and drew out the long-thonged dog-whip which for months now he had ceased to carry on the trail, finding no use for it under Jan’s leadership of the team.

A glance now showed the cause of Jan’s abrupt unordered right turn.  Close to the trail Jim saw the fresh remains of a camp-fire beside the deep marks of a sled’s runners.

“Well, an’ what of it?” said he to Jan, sharply. “’Tain’t the first time you’ve struck another man’s trail, is it?  What ’n the nation ails ye to be so het up about it, anyway?”

And then, with his practised trailer’s eyes he began to examine these tracks himself.

“H’m!  Do seem kind o’ queer, too,” he muttered.  “The sled’s a middlin’-heavy one, all right, only I don’t see but one dog’s track here, and that’s onusu’l.  Mus’ be a pretty good husky, Jan, to shift that load on his own—­eh?  But hold on!  I reckon there’s two men slep’ here.  But there’s only one man’s track on the trail, an’ only one dog.  Some peculiar, I allow:  but this here stoppin’ and turnin’ an’ playin’ up is altogether outside the contrac’, Jan.  Clean contr’y to discipline.  Come, mush on there!  D’ye hear me?  Mush on, the lot o’ ye.”

It may be that, if he had had no reason for haste, Jim Willis would have gone farther in the matter of investigating Jan’s peculiar conduct.  As it was he saw every reason against delay and no justification for close study of a trail which he was desirous only of putting behind him.  As a result he carried his whip for the rest of that day, and used it more often than it had been used in all the months since he first saw Jan.  For, contrary to all habit and custom, Jan seemed to-day most singularly indifferent to his master’s wishes, and yet not indifferent, either, to these or to anything, but so much preoccupied with other matters as to be neglectful of these.

He checked frequently in his stride to sniff hard and long at the trail.  And after one or two of these checks Jim Willis sent the end of his whip-thong sailing through the keen air from his place beside the sled clear into Jan’s flank by way of reminder and indorsement of his sharp, “Mush on there, Jan!”

When a halt was called for camping, as the early winter darkness set in, the unbelievable thing happened.  Jan, the first dog to be loosed, took one long, ardent sniff at the trail before him and then loped on ahead with never a backward glance for master or team-mates.

“Here, you, Jan!  Come in here!  Come right in here!  D’ye hear me?  Jan!  Jan!  You crazy?  Come in here!  Come—­here!”