Just before she passes, Homelander arrives and is ready to kill Billy until Mave appears and tells him she has footage of the two of them leaving a plane full of people to die from the previous season and will release it if he doesn't leave Billy and his son alone. As we end the series, Billy and the boys have been acquitted of all charges and Storm Front outed as a villain, clearing Starlight as part of the deal. So a very different start to the next season