It was the Dunder Mifflin Christmas Party, and Andy wanted to make everyone's wish come true. The problem for Erin was that Andy's girlfriend Jessica showed up to the event. She was nice to Jess, but she also got hammered on shots. Andy worried about Erin getting with Robert after the night ended, but thankfully that didn't happen.
Meanwhile, Andy told Jim and Dwight that if they prank each other they will lose their Christmas bonuses. The two guys spend the entire day pranking themselves in attempts to get the other one in trouble.