Dean and Bobby investigate the disappearance of teenage girls when Sam awakes after recovering his mended soul. Bobby still does not trust Sam and Dean and his brother travel to investigate further. They find that the abducted girls are virgins and that dragons are the responsible for the kidnappings. Dean calls Bobby and he tells the name of a specialist that may teach them how to vanquish the dragon. While Sam searches where the dragon might be hidden, Dean visits Dr. Eleanor Visyak that tells him that he needs a blade forged with dragon blood. Dean borrows a piece of the weapon with her and he goes with Sam to the sewage system where they find the missing girls. They also recovers a Fourteen Century paper and Bobby translates parts and discovers that the dragon wishes to open the purgatory's door to release the Mother of all.