As we know, he struck out for it, only to have his chum snatched almost out of his very arms by the mighty sweep of the current.

Like those on the steamboat, he had seen the cut over Sandy's eye and knew that he was injured. This made Tom all the more feverishly anxious to catch up with him, for although Sandy was a strong and good swimmer and had plenty of presence of mind in the water, if he was seriously hurt it was not probable he could stay long above the surface.

But Tom speedily found that, try as he would, he could make no gain on his chum. He heard Sandy cry out despairingly as the current swept him round a bend. The next instant Tom realized that not far below them lay some cruel rapids which the Yukon Rover had bucked that afternoon with the greatest difficulty. He knew that if something didn't happen before they got into the grip of that boiling, seething mass of water, their doom was sealed.

He almost fancied as he drifted along, allowing the current to carry him and saving his strength for the struggle he knew must come, that he could already hear the roaring voice of the rapids and see the white water whipping among the jagged black rocks, contact with which would mean death.

It was at this instant that he spied something that gave him a gleam of hope. Right ahead of them there loomed up a possible chance that he had forgotten. It was one of those willowy islets that have been mentioned as dotting the Yukon for almost its entire length. If he could but gain that, if some lucky sweep of the current would but carry Sandy in among the trees, both their lives might be saved.

And now the river played one of those freaks that rapidly running streams containing a great volume of water frequently do. Sandy's body was swept off into a sort of side eddy, while Tom felt himself seized by an irresistible force and rushed forward in the grip of the tide as it roared down to the rapids.

Horror at his utter incapacity to stem it or to do aught but yield to the rush of the stream, rendered him almost senseless for an instant. In his imagination his body was already being battered in the rapids and flung hither and thither in the boiling whirlpools.

But suddenly an abrupt collision that almost knocked the breath out of his body gave him something else to think of. Twigs brushed and scratched his face and he was held fast by branches. With a swift throb of thankfulness he realized the next instant that the impossible had happened.

A vagary of the current had swung him into the midst of the willow island and he was anchored safely in the branches of one of the trees. But he gave himself little time to think over this. His thoughts were of Sandy. Where was the Scotch boy?

Had he been swept on down the river to the rapids or had he sunk? Hardly had these questions time to flash through his mind, when he gave a gasp and felt his heart leap.