The Activity Club and the Ice Dungeon Challenge

Isaac shoots a spec shot at the table cloth. When it goes under, he hears it hit something that jingles. He carefully lifts the flap and finds the pouch of coins. That was easy!

Before Isaac can grab it, Scrooge jumps up from behind the couch and yells, drawing Isaac's attention. Scrooge leaps over the couch surprisingly quickly, and runs at Isaac.

What should Isaac do?