Lesson #1: You must control your terrified gasping.
It's possible that Jennifer (for this is Brenda's character's name, as we will soon discover) would have evaded CHM, except that as she is hiding in a stall as CHM tries to hunt her, he makes a noise and she gasps extremely loudly. This is a comedic gasp, which may as well be accompanied by a comic-book word bubble that just says "GASP!" Never do that when you are hiding from a Creepy Hood Man. This gives up her location. Now he knows she's in there!
At any rate, she is bad at hiding and eventually must run back outside to get away from him. She gets in her car, only to discover it is winched to his truck and she cannot escape. He is using a winch! This is a winch hunt! She gets out and makes a run for it, at which point she is hit by a car. (Not driven by CHM. Just driven by Some Dude.) Fortunately, the driver of the car calls an ambulance, and she is taken to Gross Negligence Memorial Hospital.
At Gross Negligence Memorial Hospital, a man with glasses and a beard comes to visit her. He behaves as her husband; they address him as her husband. If you have seen the trailer, you know perfectly well that he is not her husband. He is, instead, a weirdo. Why is he pretending to be her husband? Could it be that he has a ...
When Jennifer wakes up, this man (who calls himself "Russell Williams") explains that everything is fine. She doesn't remember that she is married to him, or that she has ever met him, or that she's ever met anyone else, or that she ever had a job where someone might know her, or anything of that nature. She has no memories of anything that has ever happened to her, but he assures her he can just catch her up, like she's reading the Wikipedia plot summary of her own life. For instance, he tells her a funny anecdote about how he had an allergic reaction once, and she laughs, ho-ho-ho, because it must have been very funny, this thing that happened one time to this man who definitely seems like her husband.
It bears mention that somewhere along here, there is also a very menacing man with a much darker beard than "Russell Williams" has. He appears at the hospital with flowers, and when the nurse asks who he is, he says he's a "concerned party." Russell eyes him suspiciously. One weirdo to a waiting room, friend! Back to him later.
Lesson #2: Don't get all the amnesia.
What is remarkable about Russell's plan (well, Fake Russell's plan) is that none of this would work if she didn't have precisely this much amnesia. He somehow knew, when he came to the hospital before she was conscious, that when she awoke, she would not open her eyes and say, "Are you kidding me? This is not my husband. This is a weirdo of my acquaintance!" Instead, she would say, "Oh. I am married to you? Interesting. That seems fine."
What's more, he somehow knew Gross Negligence Memorial Hospital would release her to him partly because—and they explain this later—he was able to identify her back tattoo.
I'm sorry, you gave her to a dude because he knew about her back tattoo? You are so getting sued, you guys! Has this hospital heard of Instagram? That's half of the reason people get back tattoos! If you can pick up anybody in the hospital by identifying their back tattoo, you could drive to Florida during spring break and bring home an entire lacrosse team.
Fortunately, Jennifer has one worthy ally: Detective Page, played by Dennis Haysbert. Yes, Dennis Haysbert! From 24 and commercials for insurance! He is not convinced that this was a simple car accident (remember, nobody knows why Jennifer ran out in front of the car, because she doesn't remember anything, including the Menaced In The Bathroom incident). He thinks there's something weird going on.
Lesson #3: Don't be seduced by the accommodations.
Fake Russell manages to remove Jennifer from the hospital, and by the time they leave, he has her fully convinced he's her loving husband. After all, he has a silver cigarette lighter engraved, "To my darling Russell, love Jennifer." (You know how hot young millennials are always giving each other engraved silver cigarette lighters. Tally ho!)
Jennifer would probably object that she has literally never seen this place before and has no memory of it and doesn't seem to have any belongings here and he isn't allowing her to speak to anyone, but fortunately for Evil Fake Russell, it's a really nice house, which papers over a lot of concerns she might otherwise have. Such as, you know, the fact that she has no reason to believe she knows this man, let alone is married to him. The house is in the woods, where, as he tells her, "The nearest neighbor is over a mile away." There is also no cell phone reception, which seems extremely unlikely for a fancypants residence, no matter how deep in the woods.
In fairness to Jennifer—no, really!—at least when she gets to the house, she's confronted by more photos that are of her and Fake Russell together. There's even a wedding picture where she looks very happy. So at least she has some reason to believe him. Not a great reason, but some reason.
The one thing that should have made Jennifer suspicious is the sheer amount of eggs that he feeds her when allegedly giving her the breakfast she loves the most. He piles scrambled eggs onto a plate and says, "Eggs, scrambled soft, just like you like them." But ... it's a mountain of eggs. It's probably five or six eggs' worth of eggs, just sitting there on a plate with nothing else. It's not that nobody eats this many scrambled eggs, but it seems like he would give a little more background. Like, "Eggs, scrambled soft, just like you like them right before you run the New York City Marathon."
There's also a very peculiar exchange where he says, "Orange juice?" And she gets a lightning-bolt expression on her face and says, "Fresh squeezed?" as if this is a breakthrough. He smiles warmly. "I'm right, aren't I?" she says. "There it is," he chuckles. "See? I told you it would all come back."
The question is ... right about what? What is she right about? That she likes fresh-squeezed juice? That juice comes from fruit? This would have made more sense if he had said, "Orange juice?" and she had paused and said, "But ... I only drink Tang. I'm right, aren't I?"
Lesson #4: Don't be too popular.
Somewhere along here, Fake Russell follows Dark Beard (a/k/a "a concerned party") home, beats him, snaps his neck, stuffs him in the Jeep, brings him back to No Reception Hall, and buries him in the backyard. Jennifer is vaguely aware of some shoveling happening in the middle of the night, but she figures it must be nothing, because apparently her form of amnesia also saps your curiosity.
To my knowledge, by the way, we never figure out who this guy was, why he was looking for Jennifer, or why nobody ever seems curious about where he went. Also not missed by anyone? Jennifer's parents, whom Detective Page eventually finds in their home, in their bed, very much not alive.
Does Jennifer have friends? An online presence? Is anyone looking for her? Did she have a job? Furthermore, is anyone looking for Jennifer's actual husband? Because, not to jump too far ahead, but as much as it would be nice to think Jennifer's husband is looking worriedly for her somewhere, it turns out he is in the trunk of a car in Fake Russell's garage, very much also not alive.
This situation seems to persist for some time (although Jennifer's parents are discovered in a substantially more advanced state of bodily transformation than True Russell The Trunk-Dweller, so a timeline is difficult to pin down). Nevertheless, nobody else figures out that Fake Russell has killed four people, nor has anyone put together that both the parents and the husband of the same woman have vanished, and that woman looks a lot like another woman who turned up with amnesia at Gross Negligence Memorial Hospital. The only thing being investigated, out of all of this, is Jennifer getting hit by a car.
Put the clues together, police! Detective Page can't do everything by himself.
Lesson #5: Prepare yourself.
Eventually, Jennifer does realize that this is not her husband. He is a weirdo! He has digitally inserted himself into photos of her and True Russell, and she really needs to get out of there. But she has a bad ankle, so her ability to flee is limited, and it doesn't help that Fake Russell has, based on the appearance of the wires, chewed through the internet connection, and because there's also no phone reception, she's in quite a bind.
Furthermore, it's not long before Fake Russell realizes that she's onto him, at which point he transforms from covertly menacing to overtly menacing and chains her to the bed while he goes to prevent Detective Page from finding her by any means necessary. He does this by clocking Detective Page and throwing him in a freezer.
She frees herself from her restraints by wiggling (THOSE ARE BAD RESTRAINTS, FAKE RUSSELL!), but she does hurt herself in the process. So later, when he returns and regains control over her, he makes her promise to "stay off it" (her ankle) by grabbing her foot and twisting it while it makes hilarious crunching and squishing noises that represent great pain. She gives in. She'll do what he wants! Just stop crushing those barbecue potato chips in front of that microphone!
The only good piece of news in this entire movie comes at about this point, when we realize that Detective Page is not dead! He is just unconscious in a freezer.
Lesson #6: Move on.
As you can imagine, all this leads to a "thrilling" climax in which Jennifer and Detective Page survive and Fake Russell does not. Later, we find Page cleaning out all the toys he's hoarded for his own daughter, who disappeared when she was ten and was never found. You see, saving Jennifer from the world's most unlikely kidnapping has freed him to move on from his own demons. And now Jennifer is going to do the same. She's pretty chipper, in fact, given that she recently had to kill a guy who killed both her husband and her parents. (And Dark Beard, whoever he was. Did anyone ever find him out in the backyard? I don't think so. RIP, Dark Beard.)