Cousins Brad and Glen have failed four times to recover a rare coin they lost. The valuable $3 gold piece, belonging to Brad's father, continues to elude them as they adventure back to different times and places.Frustrated, they head back into the limestone cave and let the mysterious foxfire hurl them into the past, not knowing where they'll wind up.This time, they land in the Yukon in December 1899 where a Northwest Mounted Policeman desperately needs their help. While destroying the whiskey cache of Swede Swenson, who is peddling hooch to the Indians, Constable McKelvey steps into a trap and a log deadfall breaks both his legs.Swede and his men are due back anytime, and the injured mountie must escape back to his cabin 30 miles away. It's 20 below zero, a blizzard is blowing up, and his sled dog team is exhausted.This is the hardest challenge the boys have ever faced. They must save themselves and the mountie from Swede Swenson and the storm. But can the fatigued dogs pull the sled with the disabled mountie 30 miles in the blinding snow at night?