We come up on Shawn, lying down in the Psych Office, wondering what just happened at Lassiter's wedding. Did Juliet really just find out he wasn't a psychic from a piece of paper she found in his jacket? Or was it all just a horrible dream? From there, the episode unfolds in the style of the film "Sliding Doors," as Shawn experiences two separate timelines set off by a "what if?" scenario. One timeline shows what would have happened if Juliet never found out that Shawn wasn't psychic; it shows them happy, in love and thinking about the next step in their relationship. The other timeline shows what really happened -- that Juliet did in fact find out Shawn wasn't a psychic. Throughout the episode, Shawn, Gus, Juliet, Lassiter and Chief Vick follow the same murder case in both timelines, and arrive at the same conclusion in both timelines, but the investigative beats they each take to get there are presented differently.
In the "real" timeline (the timeline in which Juliet finds out Shawn isn't psychic), at Lassiter's wedding, Shawn tells Gus that Juliet now knows the truth and that he fears the worst. He tells Gus how heartbroken he is and that he needs to go home. Shawn gets in a cab.
On his way home, Shawn comes across an injured woman after leaving Lassiter's wedding alone. He instructs the cab driver to rush them to the hospital because her injuries look serious. At the hospital, the nurse gives Shawn a bag of the injured woman's belongings and in it is a pair of sneakers that Shawn becomes obsessed with getting a pair of. He figures it out that the shoes are from a company called KJellen and they only sell their shoes in Sweden.
The next morning, Gus joins Shawn at the hospital and learns that Shawn has been there all night because the injured woman hasn't woken up yet and she wasn't carrying any identification when Shawn brought her in. Just then, Juliet, Lassiter and Vick show up to check out the injured woman. Shawn immediately approaches Juliet, trying to act as if nothing happened the night before, but Juliet is severely upset by Shawn's lie. Honesty is very important to Juliet and she is now faced with the fact that her relationship with Shawn was based on a lie this whole time. Shawn asks Juliet if she is going to tell Lassiter, Vick and the rest of the SBPD that he isn't really psychic; Juliet says she won't.
After taking a closer look at the woman's injuries, Lassiter suggests that the Bowie knife wounds on her body are similar to the knife wounds that killed a man named Erik Palma recently. Vick asks Shawn if he's getting any psychic readings from the injured woman. Shawn flashes back to the cab. He remembers the woman saying a word in a different language... something that sounds like "beeflog." He tells the group he has no idea what it means, but that he can take them to the area where he found her.
At the location, Shawn struggles to find any leads. A few beats later, he realizes that the woman must have been wearing shoes from Sweden because she's actually from Sweden. From this, Shawn determines that the woman was trying to tell him something in the cab but it wasn't in English; it was in Swedish. Shawn whips out his iPhone and asks Siri to translate "beeflog" (or something sounding like that) from Swedish to English. She does and the result is: "creek." Shawn alerts the group that the woman came from the creek in the woods.
They arrive at the creek and discover the body of a man lying dead in the creek. The man's name is Corey and he has the same knife wounds as Erik, the body Lassiter mentioned earlier. From this, Lassiter determines that the attacker tried to do the same thing to the woman the night before, but she managed to escape. Just then, Shawn gets a call from the hospital saying the woman is now conscious and awake.
Back at the hospital, we learn the woman's name is Elin, she is in fact Swedish and is able to speak in broken English. She tells our guys that she and her boyfriend Corey were attacked by a man in a black mask. Lassiter then shows Elin a picture of Corey dead in the creek. Shocked and hysterical, Elin confirms that is him. Lassiter shows her a picture of Erik, a man whom he believes was attacked by the same person with the same knife. Elin knows the man in the picture and tells our guys that he was her friend Erik. She then tells them she thinks the killer is Anders, her insanely jealous ex-boyfriend back in Sweden. She explains he got very violent with her after she broke it off; Anders was the reason she had to flee Sweden. She would have feared for her life everyday if she were to stay. Elin tells our guys that she's scared Anders has found her and is somewhere in town waiting to make his next move.
Armed with this info, Shawn and Gus show a police sketch of Anders to the bartender at a local Swedish expatriate bar, asking him if he knows of his whereabouts. The bartender recognizes Anders and thinks he's living with one of his regulars, a guy named Torsten. Shawn and Gus grab Lassiter and Juliet, and all four rush to Torsten's apartment. They enter, guns drawn, and find Torsten there dead.
Desperate for another lead, Shawn heads to Henry's house to talk it out. Shawn is surprised to see Juliet's stepfather Lloyd there; after the incident in Mexico, Shawn was sure those two wouldn't remain friends, but as it turns out, he was wrong. While Lloyd is grabbing Shawn a frosty mug of beer in the kitchen, Shawn asks Henry, in secret, for some help on the Elin case. Shawn breaks the case down for Henry and Henry presents his theory... a theory that Henry thinks would have been obvious to Shawn. From this, Henry realizes Shawn is there to talk about something else. Shawn comes clean and tells Henry that Juliet knows that Shawn isn't a psychic. Henry flips out. After a few beats, he calms down and reassures Shawn that everything will be okay.
Shawn calls the hospital to speak with Elin, but the nurse tells him she was picked up by a woman named Mary Pasternak. Shawn borrows Henry's truck and heads out to follow-up on this new lead. Shawn goes to question Mary and discovers Elin was the Pasternak's nanny and lived in their guesthouse. But when they go to check out her room, they see that it's been ransacked. Shawn believes that it was Anders who found Elin and took her. Mary tells Shawn that she installed a GPS tracker on Elin's phone so she'd always know where she was taking her kids. She gives her phone to Shawn and Shawn uses it to track down Elin's whereabouts.
Shawn is shocked to discover that the GPS on Mary's phone has led him to Anders' dead body. Shawn is then slashed with a knife by a person wearing a black mask. Even though Shawn can't see his attacker's face, he knows that the attacker is in fact Elin because of her distinct shoes - the Kjellens; the same shoes Shawn was admiring earlier in the hospital. Elin gets away and Shawn starts to put it all together.
This is when the two timelines converge to become one timeline; this is also the time Shawn realizes that this "other timeline" that has been playing out, was all just a hopeful dream of his. We are now fully immersed in the real timeline -- the timeline in which Juliet did find out Shawn wasn't a psychic.
Even though the audience has been watching two timelines play out simultaneously (one with Juliet knowing and one without her knowing), both end with Shawn coming to the same conclusion on the case he's been trying to solve throughout the episode. Elin, who had been permanently scarred from being abused by her stepfather in Sweden, was subsequently institutionalized, fled the mental hospital in Sweden and headed for the U.S. where she remained unstable and dangerous. She killed Erik and Corey because they fit the profile of her abusive stepfather and she killed Torsten so he wouldn't find out. And when Anders, her psychiatrist from Sweden, tried to retrieve her, Elin killed him because she didn't want to go back to Sweden.
Back at the SBPD, Shawn tells Vick, Lassiter and Juliet that Elin is the killer and that they need to put an APB out on her right away. Shawn and Gus check out the case file on Elin. They realize that Elin's mother moved to Santa Barbara after Elin's real father left her, but she was killed in a car accident that was ruled a suicide. Shawn sees that the location of Elin's mother's death is the same location that Elin left Anders' body.
Shawn and Gus head to the location and see Elin placing flowers next to where her mother died. She tells Shawn and Gus that after her mother left Sweden, she was going to send for Elin, but died before she could. Elin blames herself for her real father leaving his mother; if he never left, she would have never had an abusive stepfather, her mother would have never fled Sweden and died in a car accident in Santa Barbara, and none of this would have ever happened. Shawn and Gus appear sympathetic and tell her they want to help her, but Elin becomes violent and starts attacking them. Just as Elin is about to stab Shawn in the chest, Lassiter and Juliet show up and arrest her.
In the last scene, Juliet tells Shawn that she has been thinking about what things would have been like had she not discovered his lie. Shawn asks her to elaborate, hoping she is going to forgive him, but Juliet tells him she needs space and that Shawn should move out of their place. It's official: Juliet knows Shawn was lying to her about being a psychic, and now they are broken up.