Demons don't have hearts. Hel, the Devil's child, wishes for one. She is content with her life, andhas a girlfriend. But in the underworld, if you are 15, you must journey to the land of mortals. Hel hopes to use this to her advantage, until she meets Oscar, a kid on the same mission-except from heaven. Although she misses her home, she wants to stay in the mortal realm-and with a little help from Oscar and a mysterious woman named O, she might achieve that.