Bobby owns an electric blanket, “a twin-size, single-control, Dyna-Rest Supreme electric blanket, model DRS-T-1349-7A” (165). The blanket lies at the center of the investigation into Bobby’s invisibility; it’s a focus point around which Bobby and Alicia’s families congregate. After Bobby becomes invisible, his father and Alicia’s father inspect the blanket as part of their search for the cause. The two dads detect an overactive resistor in the blanket’s circuitry and speculate that this affected the product’s magnetic field in ways that changed Bobby. Leo also discovers that a major solar storm struck the Earth’s atmosphere on the night Bobby’s body disappeared. Alicia guesses correctly that if Bobby uses the blanket again, the effect will be reversed.

Bobby finds another blanket victim, Sheila Borden, who likes being invisible. For her, invisibility isn’t so different from the warm blanket itself—invisibility helps Sheila feel comfortable, safe, and relaxed after all the stress of her previous life. Bobby mails Sheila his blanket in case she changes her mind and wants to become visible again, leaving the decision fully in her hands.

The blanket is both the cause and the cure of the invisibility problem; as such, it launches the main plot and also ends it.