Large portions of the episode are shown from the perspective of the patient, who retains consciousness but lacks the ability to move.
The team plans to do a brain biopsy on the new patient, but he loses his eyelid movement in the operation, and with that, his only way to communicate with the doctors.
Further investigation reveals that the patient has stayed at a friend's home, in order to maintain the facade of a successful business.
Unbeknownst to his wife, he was moonlighting as a janitor, where he was exposed to cadmium, leading the team to believe that he has heavy metal poisoning.
Thirteen notices that he has a tear in the epithelial cells in his eye, and a fluorescein stain reveals ulcerative keratitis.
Cameron suggests the team does a lumbar puncture, noting that polys (polymorphonuclear leukocytes) would mean it's varicella, and lymphs, Behçet's.
As the team gets ready to perform the biopsy, Kutner notices a rash on Thirteen's wrist, where some of the patient's urine had spilled.
He deduces that it is a rash due to leptospirosis, which was transferred from rats, living in the basement where the patient had stayed.
Leptospirosis shut down the immune system during its incubation period of 2 to 4 weeks, which left his body defenseless temporarily.
Large portions of the episode are shown from the locked in patient's perspective, and Handlen states, "Basically, what we have here is a typical ep, delivered in an atypical fashion.