Susan is 'sucked in', as Death's manservant Albert puts it, forcing her to assume the role. In Soul Music Death takes a holiday from his work in an attempt to forget his more troubling memories, and a metaphysical vacancy is created. She insists on being addressed as 'Miss Susan'. After graduating - and despite being Duchess of Sto Helit - she begins a teaching career, first as a governess, in Hogfather, and then as a schoolteacher, in Thief of Time. Initially blaming Death for not saving them, she has come to accept that he is able only to grant them an eternal moment in his domain, which they have refused. Susan is introduced in Soul Music as a sixteen-year-old pupil at the Quirm College for Young Ladies, shortly after the deaths of her parents. At the end of Mort they leave Death's domain and become Duke and Duchess of Sto Helit, taking the motto Non Temetis Messor: 'Don't Fear the Reaper.' Susan is their only child. Susan is the daughter of Ysabell, Death's daughter via adoption, who is introduced in The Light Fantastic, and Mort, who was briefly Death's apprentice in the book Mort. As the series progresses, she also begins to take on roles educating children, so that, as Pratchett mentions in The Art of Discworld, she has 'ended up, via that unconscious evolution that dogs characters, a kind of Goth Mary Poppins'. Death tends to rely on her in his battles against the Auditors of Reality, particularly in situations where he has no power or influence. Being both human and supernatural, Susan is frequently and reluctantly forced away from her attempts at 'normal' life to do battle with malign supernatural forces or to take on her grandfather's job in his absence. She appears in three Discworld novels: Soul Music, Hogfather, and Thief of Time.

She is the granddaughter of Death, the Disc's Grim Reaper, and has a number of his abilities. Susan Sto Helit (also spelled Sto-Helit), once referred to as Susan Death, is a fictional character in Terry Pratchett's Discworld series of fantasy novels. Michelle Dockery as Susan in the 2006 TV adaptation of Hogfather

Terry pratchett's hogfather 2006