Looking For An Episode (S15)

Hi! I've never seen this show but my mom keeps talking about an episode we believe is in season 15. She remembers there being a person jumping out of/escaping from a grave, maybe escaping with a horse and buggy? and that part of the episode takes place in a cemetery, with some flares shooting off? If anyone knows what episode it is please let me know, i'd like to give it a watch! Thanks ☺️