Welcome the age of reason, one and all, and see how math can be personified in the shape of steam inside a kettle. 
 The enthusiasm that overflowed the novel was joyful and catching, sweeping up so many long-standard pillars of discworld and carrying them all into the future. It was a good end, if, indeed, it is the end. The cameos of so many characters lent it that inevitable feel. I don't know, since I haven't been keeping up with any official statements or the desires of Mr. Pratchett, but my intuition tells me he's wrapping things up. 
 The novel, while skimming over events so quickly as to be nothing more than steam, still showed us how fast the world could change, and how irrevocably it did so. 
 Not my favourite discworld novel, I was still thoroughly amused by Mr. Moist, who is one of my favourite characters.