Legacies 3x13 "One Day You Will Understand" Season 3 Episode 13 Promo Trailer HD - SACRIFICES - Faced with a difficult decision regarding one of his students, Alaric (Matthew Davis) enlists Kaleb (Chris Lee) and Josie's (Kaylee Bryant) help to get their perspective. Meanwhile, Cleo (guest star Omono Okojie) opens up about her past. Danielle Rose Russell, Aria Shahghasemi and Ben Levin also star. Bola Ogun directed the episode written by Cynthia Adarkwa (313). Original airdate 5/20/2021.