Heyes and Curry meet an old prospector who, thinking that he hasn't long to live, gives them a map to a gold mine. The boys decide to mine it in company with some other men from the town.
Things go well for a while, with each man gathering his gold dust, and sizeable fortunes build up. However, one day Heyes and Curry discover that their precious cache of gold dust has been stolen, presumably by one of the men who is working on the site.
Meanwhile the old prospector has turned up - he hadn't been dying, but was simply weighed down by all that gold dust and was suffering from a hernia. He joins the rest of the boys working the mine, and although Heyes and Curry are extremely annoyed at the loss of their gold, things carry on until one day winter arrives with a rush and the men discover that they are snowed in for the winter in a cabin high up in the mountains.
The only way for Heyes and Curry to recoup their missing gold is to win it back at cards. They suspect that the thief is a dodgy Doctor of Medicine calling himself Dr. Chauncy Beauregard. When Heyes and Curry introduce a new card game called Montana Red Dog the Doctor suddenly finds himself on a losing streak.