Alan risks his life to save his brother Peter from Ilaria CEO Constance Sutton, only to see him re-captured by Vectors. Julia Walker deals with the mystery of her "cure" while her half- brother Daniel confronts their father, Dr. Hatake, about being abducted as a child.

The CDC teams learns the real purpose of the infection and Alan and Julie make a perilous journey to retrieve the canister that has the original source virus.