This is my favorite of the Discworld series that I have read so far. I prefer Pratchett books that have Sam Vimes as the main character. In this installment, Vimes gets transported back in time (along with the deviant criminal he is chasing at the time) and relives a moment in his past from a different angle. He joins the Night Watch and prepares himself for the chance to remake a dark point in the history of Ankh-Morpok