As Amy experiences symptoms of the virus that indicate she is close to turning, Brad brings everyone together, and Lila and Sykes race to perfect an anti-viral medicine to save her from Fanning.

Cast: Mark-Paul Gosselaar, Saniyya Sidney, Jamie McShane, Caroline Chikezie, Emmanuelle Chriqui, Brianne Howey, McKinley Belcher III, Henry Ian Cusick, Vincent Piazza, Jason Fuchs, Melanie Jeffcoat, Taisha Perez, Victoria White