The ice-locked river upon which they found themselves was a stream of considerable size which flowed north, with a decided trend to the eastward. The muskeg and tundra had given place to the rocky formation of the barren lands which cropped out upon the banks of the river in rock reefs and ledges. Scrub trees and bushes in sickly patches fringed the banks, their leafless branches rattling in the wind.
An hour's travel on the snow-covered ice of the river brought them to a sharp bend where a river flowed in from the eastward, and there, almost at the confluence of the two streams, stood the solitary rock cairn, a monument some seven feet in height and five feet in diameter at its base.
"He didn't cache no great sight of meat heah," observed Waseche as, one by one, they removed the stones of the cairn. "We got a plenty, but I counted on this fo' the dawgs." Even as he spoke, they came upon a flat stone midway of the pile, which required their combined strength to displace. With a harsh, grating sound it slid sidewise into the snow, disclosing a considerable cavity, in the centre of which lay, not the expected cache of caribou meat, but a human skull, whose fleshless jaws grinned into their startled faces in sardonic mockery. Beside the skull lay a leaf torn from Carlson's notebook, and in Carlson's handwriting the words:
FOL. RIV. 2d N to CREEK OF STEAM. FOL. UP CREEK 2m. CAMP W BANK IN OLD MINE TUNNEL. DISCOVERY 100ft. E. TUNNEL MOUTH. 1 ABOVE CLAIM—STAKED FOR PETE MATEESE. LOOK OUT FOR WHITE INJUNS.
"Ol' mine tunnel! White Injuns!" exclaimed Waseche. "I tell yo' what, son: so fah, Carlson's maps has hit out, but when he begins writin' about white Injuns an' ol' mine tunnels, an' cachin' skull bones, 'stead of meat! It's jest as I tol' yo'! We-all got to keep on now, but I sho' wisht we'd neveh found Carlson an' his crazy maps."
"Whose skull do you suppose it is? And why did he cache it, I wonder?" asked Connie, as he handled gingerly the gruesome object.
"Seahch me!" said the man, glancing at the weather blackened skull. "Come on, le's mush."
As they advanced the surface of the surrounding land became more broken and the river descended rapidly in a series of falls, enclosed by the freezing spray, in huge irregular masses of green-hued ice, which impeded their progress and taxed to the utmost the skill of the drivers and the tricks of the trail-wise dogs in preventing the sleds from being dashed to pieces upon the slope of the ice domes, from whose hollow interiors came the muffled roar of the plunging falls.
The dogs were again on half ration, and even this was a serious drain upon the supply of meat. The walls of the river became higher until, on the second day, they were threading a veritable canyon. At noon the light dimmed suddenly, and the two gazed in surprise at the sun which glowed with a sickly, vapoury glare, while all about them the air was filled with tiny glittering frost flakes, which lay thick and fluffy under their feet and collected in diamond flashing clusters on the rocks and bushes of the canyon walls.