'Souls of the Departed ' has a new, twisted premise for known fairy tale show: a trip to hell, or correction, to the Underworld. I am pleasantly surprised that a show like Once Upon a Time still finds new ways to surprise us, and give new reamls to discover. I would not have imagined such environment for a show that started so light-hearted and with well known fairy tales. OUAT has shown hints of going dark earlier too with Emma Swan going dark. Personally not the best way I would have wanted the mid-season go, but it's nice darker touch to the show. It has great new characters too like Hades.