The three rules of the Librarians of Time and Space are: 1) Silence; 2) Books must be returned no later than the date last shown; and 3) Do not interfere with the nature of causality.
Guards! Guards! is one of the many novels in the series known as Discworld. My husband recommended this one, as he was a fan. Since I make him read things all the time (Game of Thrones and Hunger Games spring immediately to mind), I thought I would oblige him.
This volume of Discworld is set in Ankh-Morpork, and tells the story of a secret plot to overthrow the current ruler, the Patrician, and install a puppet king. This is meant to be accomplished by the Elucidated Brethren of the Ebon Night, run by a Supreme Grand Master, who has the idea to use a dragon to terrify the populace and inspire change. Not surprisingly, this does not go as planned. One of the biggest hitches in this plan is a group called the Night's Watch (I am the sword in the darkness...no wait, wrong book). The Night's Watch is run by Captain Vimes, an alcoholic who starts to take his job and his life more seriously when a new volunteer, Carrot, joins the ranks. Carrot was raised by dwarves, even though he is obviously not one, with his enormous stature and strength. He enjoys following the exact letter of the law, which is troubling for the Watch since they stopped having laws in Ankh-Morpork long ago. The arrival of the dragon spurs the men to reluctant action, with the assistance of a dragon expert, Lady Ramkin. They are also aided by The Librarian, who happens to be an orangutan.
The book is rather ridiculous, and mostly in the best ways. It took a long time for me to get into it, and it doesn't really resolve a great deal by the end (series and all that jazz). However, the characters are great fun. It's not a book I expect to really stay with me, and not a series I'm sure I'm dying to pursue, but it was a fun way to spend some time.