The third season continues with Derek and Scott trying to help Issac remember where Erica and Boyd are. Both Derek and Scott, and Lydia and Allison discover that the location is an abandoned bank. Derek and Scott launch a mission to recover them just when Paul discovers the real reason why they were left alive for three months; they were prevented from turning for three months. Making them vicious and hungry for blood. They discover that Derek’s younger sister, Cora, is alive and one of the two victims of Deucalion. Scott is forced to tell Allison the truth about how her mother got bit.