When a young man comes to Bunker Hill ravaged by a drug-resistant strain of HIV, James attempts a radical anti-viral treatment. Also, Walter must work quickly when his daughter's best friend contracts a fatal flesh-eating bacteria, and James makes a connection with Louis Keating's nurse.

Radical treatments are used to help a teenage girl with a rare skin blistering disorder heal in time for her prom; and James is tempted to try his experimental cure on Louis Keating as his GSS condition worsens. On a personal front, Malik is bothered by how James and Zoe relate to each other; at the same time, Zoe has an awkward encounter with James' new crush, Nina.