The skit started with a black and white version of The Tonight Show on Wednesday as Fallon conducted an old-school interview with Olsen.
Olsen and Fallon continue to travel through time, presenting different versions of The Tonight Show through the decades. The duo donned different outfits and hairstyles for each time period.
Olsen begins to question what is happening and whether Fallon is causing this, due to wanting things to feel more normal before the COVID-19 pandemic.
WandaVision star Kathryn Hahn is later revealed to be behind the time bending, a call back to her role on the show as the villainous Agatha Harkness.
Fallon and Olsen then had a traditional, modern-day interview where the actress reacted to memes inspired by WandaVision and discussed starring in Marvel's upcoming Doctor Strange sequel and how it connects to WandaVision.
"It is a complete tee-up for my character," Olsen said.