the weather was mild, for the short, oppressive northwest summer was rapidly approaching. during the middle of the day the sun was hot, and the boys perspired freely. by and by would come the billions of mosquitoes to render life unbearable. those pests often kill bears and wolves by blinding them, and the man who does not wear some protection is driven frantic, unable to eat, sleep, or live, except in smothering smoke. jeff had said that he meant to complete the work, if possible, and start down the yukon before that time of torment arrived.

for two days the boys wrought incessantly. they had learned how to wash and purify the gold in the crude way taught them by the old miner, and the rich reward for their labor continued. jeff had brought back on his previous visit to dawson city an abundant supply of strong canvas bags, in which the gold was placed, with the tops securely tied. these were regularly deposited in the cavern where the party made their home, until a row of them lined one side of the place. it was a striking proof of the wonderful richness of their find, that one of these bags was filled wholly with nuggets, which must have been worth fifteen or twenty thousand dollars.

early on the afternoon of the third day another thought struck frank mansley, and he ceased shovelling gravel into the rocker for his companion.

"what is it now?" asked roswell with a smile.

"don't you remember that on the first day we arrived here, while we were prospecting up the little stream, we saw that friend of ike hardman?"

"yes, of course."

"well, we never told jeff about it."

"i declare!" exclaimed roswell. "how came we to forget it?"

"this gold drove it out of our minds. i never thought of it until this minute. i tell you, roswell, i believe something has gone wrong."

and frank sat down, removed his cap, and wiped his moist forehead with his handkerchief.

"what could have gone wrong?" asked the other lad, who, despite his jauntiness, shared in a degree the anxiety of his friend.

"all the gold we have gathered is in the cavern. i believe hardman and those fellows are in the neighborhood and mean to steal it."

"it's a pity we didn't think of this before," said roswell, laying down his shovel. "let's go back to the cavern and keep watch till jeff comes back."

inspired by their new dread, they hastily gathered up what gold had been washed out, stowed it into another canvas bag, and then frank slung it half filled over his shoulder and started for the cavern, something more than an eighth of a mile away.

they walked fast and in silence, for the thought in the mind of both was the same. from the first the most imprudent carelessness had been shown, and they could not understand how jeff ever allowed the valuable store to remain unguarded. it is true, as has already been stated, that the section, despite the rush of lawless characters that have flocked thither, is one of the best governed in the world, and no officers could be more watchful and effective than the mounted police of the northwest; but the course of our friends had much the appearance of a man leaving his pocketbook in the middle of the street and expecting to find it again the next day.

a bitter reflection of the boys was that this never would have been the case had they told jeff of the presence of the suspicious individual in the neighborhood. if anything went amiss, they felt that the blame must rest with them if matters were found right, they would not leave the cavern until one or both of their friends returned.

when half the distance was passed, roswell, who was in the load, broke into a lope, with frank instantly doing the same. a minute later they had to slacken their pace because of the need to climb some bowlders and make their way through an avenue between massive rocks, but the instant it was possible they were trotting again.

it had been the custom for the gold-seekers to take a lunch with them to the diggings. this saved time, and their real meal was eaten in the evening after their return home.

the moment roswell caught sight of the round, irregular opening which served as the door of their dwelling, he anxiously scanned it and the pile of wood and embers on the outside, where the fire was kindled for cooking purposes. the fact that he saw nothing amiss gave him hope, but did not remove the singular distrust that had brought both in such haste from the diggings.

he ran faster, while frank, discommoded by the heavy, bouncing bag over his shoulder, stumbled, and his hat fell off. with an impatient exclamation he caught it up, recovered himself, and was off again.

as he looked ahead he saw roswell duck his head and plunge through the opening.

"is everything right?" shouted frank, whose dread intensified with each passing second.

before he could reach the door out came his cousin, as if fired by a catapult. his eyes were staring and his face as white as death.

"right!" he gasped; "we have been robbed! all the gold is gone!"

"we have been robbed! all the gold is gone."

"we have been robbed! all the gold is gone."

and overcome by the shock the poor fellow collapsed and sank to the ground as weak as a kitten. frank let the bag fall and straightened up.

"no; it cannot be," he said in a husky voice.

"look for yourself," replied roswell, swallowing a lump in his throat and turning his eyes pitifully toward his comrade.

a strange fear held frank motionless for several seconds. despite the startling declaration of his cousin, a faint hope thrilled him that he was mistaken, and yet he dared not peer into the interior through dread of finding he was not.

reflecting, however, upon the childish part he was playing, he pulled himself together, and with the deliberation of jeff graham himself bent his head and passed through the door.

enough sunlight penetrated the cavern to reveal the whole interior in the faint illumination. when they left that morning the row of canvas bags was neatly arranged along the farther wall, where they stood like so many corpulent little brownies.

every one had vanished.

frank mansley stared for a moment in silence. then he stepped forward and called in a strong, firm voice:

"come, roswell, quick!"

the other roused himself and hastily advanced.

"take your revolver," said frank, as he shoved his own into his hip-pocket, and begun strapping jeff's cartridge belt around his waist. as roswell obeyed, his cousin took the winchester from where it leaned in one corner.

"now for those thieves, and we don't come back till we find them."