How does Tom figure out where the money is?

After the burial, Tom and Huck steal away from the crowd to talk. Huck reveals that it was he who had followed Injun Joe from the tavern to the widow's house. Tom, in turn, surprises Huck by announcing that he knows the whereabouts of the treasure. Betting all his worldly possession that the treasure is hidden in McDougal's cave, Tom convinces Huck to return to the cave and fetch it. The two boys take a skiff down the river and enter the cave through the tiny hole that Tom and Becky had previously climbed out of. Leading Huck through the familiar passageways, Tom stops at the large rock, inscribed with a cross made from candle smoke, where he had encountered Injun Joe inside the cave. After digging in the clay earth, the boys uncover the box of money, transport the money into bags, and head back to town.