Mort, an awkward teenager, is recruited by Death as his apprentice. One evening when covering for Death, he decides not to follow the rules and allow Princess Keli to live, but this has a disastrous consequence on reality which he must try and fix.
This is the fourth novel in the Discworld series and is probably my favourite so far. It is full of humour and I loved the characterisation of Death. I look forward to seeing him in more Discworld novels.