Spoilers ahead for WandaVision Episode 4, "We Interrupt This Program." After spending three episodes inside a mysterious sitcom starring Wanda Maximoff and Vision, WandaVision has finally pulled back the curtain on Westview's picture-perfect facade. Its fourth episode begins with Captain Monica Rambeau reappearing after the blip — when all of the people who disintegrated after Thanos' snap were brought back into existence during Avengers: Endgame — and learning that five years have passed and her mother, Maria Rambeau, is dead.
It turns out that Monica is an agent for S.W.O.R.D. (which has been renamed to Sentient Weapons Observation Response Division), the government agency founded by her mother that responds to threats both extraterrestrial and otherwise. Her first mission upon her return? Helping the FBI investigate a missing persons case in — you guessed it — Westview, New Jersey. When she arrives, she finds FBI Agent Jimmy Woo already at the scene, perplexed by local law enforcement's assertion that Westview doesn't exist despite the fact that it's right in front of them. The two attempt to investigate further before Monica is literally sucked into the force field that surrounds the town, completely vanishing from view.
Now here's where things start to get really interesting. Just one day later, S.W.O.R.D. has set up a multi-agency response base outside of Westview, and that's where we (once again) meet Darcy Lewis, who was first introduced to the MCU in the early Thor movies but has now reappeared as an astrophysicist brought in to help figure out what's going on with the town. Dr. Lewis is the first of all the experts to get any leads when she discovers the broadcast frequency for the WandaVision sitcom, providing the agencies a glimpse into what Wanda is doing (and confirming that Vision is indeed dead in this universe).
The episode provides the backstory for countless moments that have puzzled and intrigued WandaVision fans, including the toy S.W.O.R.D. helicopter Wanda discovers in the bushes, the person trying to contact Wanda over the radio, and the man in a beekeeper outfit who emerged from the sewers. It also reveals that most of the people in Wanda's Westview (notably excluding Agnes) are actually real people who have somehow been sucked into her fantasy sitcom world and forgotten their real identities — the same thing that seemingly happened to Monica.
Most notably, the episode fills in the gaps of the conversation Wanda had with Monica before forcefully expelling her from town. Wanda calls Monica an outsider, confirming that she played a role in creating this alternate reality and is actively preserving it by rejecting the things (and people) who threaten to reveal the truth. It makes sense that she'd do this: after the blip, everyone else was reunited with their disintegrated loved ones, but Wanda was still alone, mourning Vision.
One of the most shocking moments comes toward the end of the episode, when Wanda turns around to see Vision not as the jovial android he's been throughout WandaVision, but as the discolored, lifeless shell he was after Thanos ripped the Mind Stone out of his head in Avengers: Infinity War. She looks down, visibly shaken, but when she looks back up at Vision again he's back to his normal "living" self. The sitcom reality might have righted itself, but things in Westview are far from OK.