The events of WandaVision come to a head, and the destinies of all who took part are determined.
Agatha Harkness holds Billy and Tommy Maximoff hostage, but Wanda Maximoff frees them and sends the two to their rooms. When she is attacked by Maximoff, Harkness absorbs her chaos magic and a sliver of her life essence. The witch offers to sustain the Westview Anomaly for Maximoff if she surrenders her magic, but is tossed aside instead. When the hostile White Vision lands in Westview, Maximoff mistakes him for her husband, who arrives in time to save her from the doppelgänger. Maximoff apologizes to Vision for not revealing the truth about Westview earlier, however he assures his understanding as to why she made her false world.
As their enemies reemerge, Vision ascends to the skies to fight his white counterpart while Maximoff chases Harkness down to the town center. There, Harkness informs her adversary about her depiction in the Darkhold: forged into reality with power exceeding those of the Sorcerer Supreme, the Scarlet Witch is destined to destroy the world. When Maximoff attempts to deny any correlation of legend to her, Harkness proceeds to gaslight her by releasing every Westview resident from her thrall, leading them to bombard their former captor with emotional pleas and haunting revelations. Overwhelmed, Maximoff inadvertently releases another burst of magic that nearly kills the civilians. At home, Billy senses his mother's emotional turmoil, prompting him and Tommy to come to her aid.
Meanwhile, "Pietro" has kept Monica Rambeau prisoner inside his house. She soon discovers Pietro's real identity as Ralph Bohner along with an enchanted necklace on him, which she removes to free Bohner from Harkness' control. At the S.W.O.R.D. base, Jimmy Woo is brought in handcuffs to Tyler Hayward, who remains keen on assassinating Maximoff and covering it up with a false narrative. But Woo manages to covertly steal a phone, later releasing himself from his binds and contact his FBI allies nearby.
Egged on by Harkness, Maximoff complies with the Westview residents' pleas for liberation, initializing the Anomaly's destruction. However, this causes her Vision and children to start disintegrating, forcing her to halt the process. As the barrier has partially opened during this, Hayward uses the opportunity to funnel his men into the town, who are then joined by White Vision and Harkness as they descend upon the family. The Maximoff boys disarm S.W.O.R.D., prompting Hayward to emerge with a firearm and attempt to kill them. He is stopped by Rambeau and Billy, and his attempt to flee is thwarted by Darcy Lewis. Vision confronts his doppelgänger and leads him to contemplate his existence with a philosophy lecture, allowing him to restore the original memories inside White Vision.
White Vision flees, now aware of his past. As Vision reunites with his boys, Maximoff subjects Harkness to a hallucination which revisits her 1693 witch trial. But her attempt to torment Harkness with zombie witches backfires when they recognize her as the Scarlet Witch. Returning to reality, Maximoff repeatedly blasts Harkness with chaos magic, seemingly allowing her to absorb it all. This is revealed to be a ruse that gives Maximoff cover to cast protection runes within the Anomaly, rendering Harkness powerless. She subsequently reclaims her chaos magic, thus fully morphing into the Scarlet Witch. The defeated Harkness is then imprisoned within her "Agnes" persona by Maximoff as she reunites with her family, who recognize that Westview is no longer a place for them.
As the Anomaly begins to dissipate, the family returns home for a final time, where Maximoff bids goodbye to her boys in bed. She and Vision reflect on the history they have shared, embracing each other before the Anomaly is completely erased, taking the family with it. Maximoff returns to the town square and reconciles with Rambeau amid the scowls of her former thralls, before ultimately fleeing Westview. Later, the FBI arrive and arrest Hayward as Woo assumes authority, while Rambeau is summoned to outer space by an old friend of her mother's. Sometime later, Maximoff has settled in the wilderness and begun to study the Darkhold when she hears her boys crying out for help.
- Elizabeth Olsen as Wanda Maximoff/Scarlet Witch
- Paul Bettany as Vision / White Vision
- Debra Jo Rupp as Sharon Davis/"Mrs. Hart"
- Teyonah Parris as Monica Rambeau
- Evan Peters as Ralph Bohner/"Pietro Maximoff"
- Randall Park as Jimmy Woo
- Kat Dennings as Darcy Lewis
- Kathryn Hahn as Agatha Harkness/"Agnes"
- Julian Hilliard as Billy Maximoff
- Jett Klyne as Tommy Maximoff
- Josh Stamberg as Director Tyler Hayward
- Emma Caulfield Ford as Sarah Proctor/"Dottie Jones"
- Jolene Purdy as Isabel Matsueda/"Beverly"
- David Payton as John Collins/"Herb"
- David Lengel as Harold Proctor/"Phil Jones"
- Asif Ali as Abilash Tandon/"Norm"
- Selena Anduze as Agent Rodriguez
- Amos Glick as Dennis the Delivery Man
- Kate Forbes as Evanora Harkness
- Lori Livingston as FBI Skrull Agent
- Chase Yi as EMT
- Shane Berengue as Tactical S.W.O.R.D. Agent (uncredited)
- Isaiah Knott as Townsperson (uncredited)
- Wayne Riggan as S.W.O.R.D. Air Force Officer (uncredited)
- Paul Trunz as Townsperson (uncredited)
- Tony Lazzara as Townsperson (uncredited)
- Vladimir Tevlovski as Townsperson (uncredited)
- Tommy Rosales as Townsperson (uncredited)
- Tim Mikulecky as Townsperson (uncredited)
- Brandon Davis as Townsperson (uncredited)
- Tarah Paige as Townsperson (uncredited)
- Heath Hensley as Townsperson (uncredited)
- Amanda Hall as Townsperson (uncredited)
- Justin Ellings as Townsperson (uncredited)
- Todd Bloomer as Townsperson (uncredited)
- Mark Wagner as Townsperson (uncredited)
- Kevin Foster as Townsperson (uncredited)
- Alice Rietveld as Witch (uncredited)
- Sierra Hoyle as Witch (uncredited)
- Neraida Bega as Witch (uncredited)
- Cina McKenna as Witch (uncredited)
- Noelle Mulligan as Witch / S.W.O.R.D. Tactical Team (uncredited)
- Vanessa Vander Pluym as Witch (uncredited)
- Sarah Molasky as Witch (uncredited)
- Alex Smith as S.W.O.R.D. Tactical Team (uncredited)
- Craig Baxley, Jr. as S.W.O.R.D. Tactical Team (uncredited)
- Jay Lynch as S.W.O.R.D. Tactical Team (uncredited)
- Marilyn Giacomazzi as S.W.O.R.D. Tactical Team (uncredited)
- Rex Reddick as S.W.O.R.D. Tactical Team (uncredited)
- Richard Burden as S.W.O.R.D. Tactical Team (uncredited)
- Timothy Rigby as S.W.O.R.D. Tactical Team (uncredited)
- Tom Harper as S.W.O.R.D. Tactical Team (uncredited)
- Tom McComas as S.W.O.R.D. Tactical Team (uncredited)
- Ben Scott as S.W.O.R.D. Tactical Team (uncredited)
- Chris Patton as S.W.O.R.D. Tactical Team (uncredited)
- Molly Culver as S.W.O.R.D. Tactical Team (uncredited)
- Janey Hahn as S.W.O.R.D. Tactical Team (uncredited)
- Jeremy Fry as S.W.O.R.D. Tactical Team (uncredited)
- James Mitchell-Clyde as S.W.O.R.D. Tactical Team (uncredited)
- Roman Mitichyan as S.W.O.R.D. Tactical Team (uncredited)
- Robert Downey, Jr. as Tony Stark/Iron Man (archive footage; uncredited)
- Mark Ruffalo as Bruce Banner/Hulk (archive footage; uncredited)
- Letitia Wright as Princess Shuri (archive footage; uncredited)
- James Spader as Ultron (archive footage; uncredited)
- Chris Hemsworth as Thor (archive footage; uncredited)
- Josh Brolin as Thanos (archive footage; uncredited)
- Paul Rudd as Scott Lang/Ant-Man (archive footage; uncredited)
- Westview, New Jersey
- New Jersey
- Wanda Maximoff's Hideout
- New York City, New York (memory)
- Avengers Tower (memory)
- Johannesburg, South Africa (memory)
- Novi Grad, Sokovia (memory)
- Novi Grad Church (memory)
- Golden City, Wakanda (memory)
- Wakanda Medical Center (memory)
- Avengers Compound, New York (memory)
- Schkeuditz, Germany (memory)
- Leipzig-Halle Airport (memory)
- Edinburgh, Scotland (memory)
- Salem, Massachusetts (vision)
- Quantico, Virginia (mentioned)
- Westview Anomaly
- Ultron Offensive
- Infinity War
- Avengers Civil War
- Infinity Stones
- Enchanted Necklace
- Bulletproof Vest
- Big Red
- Oz the Great and Powerful
- Squeaky Shine (poster)
- Fresh-O (poster)
- Hydra Soak (poster)
- Westview Dairy Milk (poster)
- Iron Man Armor: Mark XLV (memory)
- Iron Man Armor: Mark XLIV (memory)
- Arc Reactor (memory)
- Regeneration Cradle (memory)
- Kimoyo Beads (memory)
- Mjølnir (memory)
- Asgardian Armor (memory)
- Ultron Sentries (memory)
- Infinity Gauntlet (memory)
- Ant-Man Suit (memory)
- Pym Particles (memory)
- Bees (mentioned)
- Eastview Sheriff's Office
- Avengers (memory)
- Salem Coven (vision)
- Sorcerer Supreme
- Maria Rambeau
- Nick Fury
- Sarah Proctor's Daughter
- Isabel Matsueda's Husband
- Steven Seagal
- Ship of Theseus
- This is the first and only WandaVision episode to have both a mid-credits scene and a post-credits scene.
- Wanda Maximoff finding just a pair of boots where Agatha Harkness stood after throwing a car at her is a reference to the death of the Wicked Witch of the East in the The Wizard of Oz.
- The philosophical confrontation between Vision and White Vision about the Ship of Theseus' Paradox is a direct reference to the comic book issue Avengers Vol. 1 #6, where a future version of the Vision uses the Paradox to contest his present counterpart of them being the same being after millennia of cybernetic replacements.
- The episode reintroduces the Darkhold with a new design.
- The post-credits scene where Maximoff reads the Darkhold has a subtle hint at Doctor Strange's main theme, teasing Doctor Strange in the Multiverse of Madness.
- In an interview, Matt Shakman said that a scene was filmed in which Monica Rambeau, Ralph Bohner, Darcy Lewis, Billy, and Tommy Maximoff went into the basement of Ralph Bohner's House, intending to steal the Darkhold, only to be attacked by Señor Scratchy, who would have turned into a demonic figure. The scene was not used because it was considered "a huge detour in the middle of everything" and thus the VFX was never finished.
- Doctor Strange was originally planned to appear in the final episode, but the character was removed to keep the focus on Maximoff.
- The post-credits scene was later changed, altering the amount of trees, removing the birds and adding more light in certain areas.