WARNING: The following contains spoilers for WandaVision Episode 4, "We Interrupt This Program," now streaming on Disney+.
In its fourth episode, "We Interrupt This Program," WandaVision takes a break from the show's previous sitcom style and instead focuses on the people working to solve the mystery behind Westview. In the process, Darcy Lewis (Kat Dennings) returns to the franchise for the first time since 2013's Thor: The Dark World to aid S.W.O.R.D. and the FBI in their investigation, revealing some of what she's done since the God of Thunder's second solo outing in the process.
In 2011's Thor, Darcy was a political science student working as Jane Foster's assistant and Dr. Erik Selvig's intern. Over the course of that film, she learned more about Asgard and Thor. Later, in The Dark World, Darcy helped investigate the various portals -- which Malekith used to go to Earth in search of the Aether -- opening up across the planet. After the battle with Malekith, Darcy returned to school and at some point got her doctorate in astrophysics.
At the start of WandaVision's fourth episode, Darcy and several other scientists are brought in to help figure out what's happening with Westview. Using her tools, Darcy detects massive amounts of CMBR (cosmic microwave background radiation) in the town. CMBR, for its part, is a type of radiation left over from the earliest days of the universe.
Soon, though, Darcy realizes there's a broadcast frequency hidden inside the radiation flux, so she requests an old TV to tap into it. This allows her to basically view the "sitcom" reality that Wanda has created. The sassy yet ever-resourceful Darcy then spots a radio next to Wanda when she met with Dottie and the ladies in WandaVision's second episode. Hoping to contact the Avenger, Darcy and Agent Jimmy Woo use radio wave transmitters to send a message to Wanda. This, of course, confirms it was Woo trying to communicate with Wanda in the show's earlier episodes.
This proves to be a massive breakthrough, as Darcy and Jimmy can tell that Wanda is able to hear their message. Still, Wanda uses her abilities to skip the signal in places and thus reset her world, which could prove to be a problem for S.W.O.R.D. going forward. This revelation also indicates Wanda is the one who has created Westview's altered reality.
The mystery surrounding Wanda and Westview requires Darcy to put all of her academic knowledge and the skills she's acquired since The Dark World to the test. After all, this goes beyond just bending space and time to create rifts, because as Monica Rambeau reveals when she's booted out the town, this is Wanda restructuring and manipulating reality. So while Darcy is yet to get her coffee or proper answers, at least her role in helping define Phase Four of the MCU is even bigger than fans expected.
Written by Jac Schaeffer and directed by Matt Shakman, WandaVision stars Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Paul Bettany as Vision, Randall Park as Agent Jimmy Woo, Kat Dennings as Darcy Lewis, Teyonah Parris as Monica Rambeau, and Kathryn Hahn as Agnes. New episodes air Fridays on Disney+.