When the sketch embedded above begins, you think you know what's going to happen. All of the 'SNL' cast members at the office Halloween party will show off their increasingly elaborate costumes and accompanying impressions. But no! What ends up happening is far stranger and more specific.

After introducing the bulk of the cast in their fairly normal (and fairly lame) costumes, Kate McKinnon shows up dressed as the dancer from Sia's "Chandelier" music video. And it's pretty funny. Then guest Jim Carrey arrives dressed in the same costume. And it's funnier. Then they two of them decided to have a dance-off to prove their supremacy. And it's still funny. Then the dance-off grows steadily more elaborate, with Carrey and McKinnon escaping from the set, dancing into the audience, running in Lorne Michaels and dancing through sets from previous sketches. And it becomes, well, kind of fantastic.

There's only one real joke here, but it's a joke done surprisingly well. Both Carrey and McKinnon nail the physicality, showcasing a distinct lack of shame as they leap into the audience in costumes that most people wouldn't wear in public. It's also a chance for one of the show's most talented ladies to get into a mugging contest with the king of Hollywood mugging and she more than holds her own. Way to go, Ms. McKinnon.

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