Blood Line Fever

S1, E4: Blood Line Fever

Available on iTunes, Funimation, Hulu, Crunchyroll
S1 E4: Leo spots a person with a crimson wing-like aura, whom Klaus later determines to be one of the vampiric Blood Breeds. Soon after, the vampire expert "Lucky" Abrams arrives in town to use Leo's vision to learn more about the Blood Breed threat.