The day of Susannah's EEG appointment, she outright refuses to go. Stephen finally convinces her to get in the car. As she and Stephen sit in the backseat, Susannah hears Allen say that she's a slut. When Susannah angrily calls him out, Allen seems surprised. Susannah unbuckles her seatbelt and opens the door to jump out of the car, but Stephen grabs her before she can jump. Mom screams, and Stephen tells Susannah in a level voice that her behavior isn't okay. When Allen engages the child locks on the car, Susannah panics and screams for them to let her out until she becomes too exhausted to scream.
Susannah's sudden distrust of her family members shows the potential that illness, particular mental illness, has to damage families and even tear them apart. Stephen's change in tone suggests that his relationship to Susannah will also change as he's forced to take on the role of a caregiver and protector, not an equal partner.
When Susannah wakes, they're in Chinatown. She demands coffee and food, and Allen sharply navigates to a diner. Stephen thwarts Susannah's escape attempt, so Susannah walks into the diner, followed by Stephen. Despite the long line of people waiting, Susannah seats herself at an empty booth and shouts that she wants coffee and an egg sandwich. Stephen is mortified and asks for the order to go. The man behind the counter graciously cooks a sandwich and gives Susannah a hot cup of coffee. Susannah feels powerful as she gets back into the car and throws the sandwich onto the floor, insisting she's not hungry.
This is a horrifying change in personality for Susannah. It's not just wholly inappropriate; it's an embarrassing offense in Stephen's eyes. Further, this new identity of hers is that of a person who believes they have a great deal of power, though this new Susannah has very little in reality. Even this new, strange identity has multiple parts to it.
In Dr. Bailey's waiting room, Susannah has no sense of time as she waits. She feels almost drugged. Finally, a technician calls Susannah into an exam room and glues electrodes to Susannah's scalp. The technician instructs Susannah to close her eyes, and then leads her through breathing exercises and shines a pulsing light into Susannah's eyes. When the test is over, the technician removes the electrodes and informs Susannah that there's nothing wrong; it's all in her head, and she's just stressed.
The technician's assessment is almost uncanny—as Cahalan will soon reveal, her illness is "all in her head" in a sense, but in a way that not even an EEG can monitor. This illuminates how intricate the brain is and how hard it can be to diagnose problems with it. While the tech is probably right about many patients, her lack of curiosity again prevents Susannah from getting the help she needs.
When the technician leaves, Susannah laughs. She realizes that Mom and Allen must've hired an actress to pose as the technician to punish her for bad behavior. When Susannah returns to the waiting room, Mom is the only one still there. Susannah accuses Mom of setting her up and informs her that she's too smart to fall for tricks. Mom's mouth falls open in horror, but Susannah interprets it as mock surprise.
Again, a hallmark of Susannah's disease is this sense of paranoia that turns her against her family members. This in turn makes it more difficult and heartbreaking for her family to care for her, if only because Susannah doesn't interpret their caring actions for what they are.