Terry Pratchett's "MORT"
Terry Pratchetts MORT
Adapted for the stage by Stephen Briggs, this tells the story of Mort, who has been chosen as Death's apprentice. He gets board and lodging and free use of company horse, and doesn't even need time off for his grandmother's funeral. The trouble begins when instead of collecting the soul of a princess, he kills her would-be assassin, and changes history.