The Garderobe of Death
(The Chronicles of Brother Hermitage #2)
by Howard of Warwick (2015)

What the hell is a Garderobe ??

As the book explains, it is a long-drop (toilet) constructed within a castle designed to deposit fecal matter outside the building. Only this time it’s internal and has been boarded up..

And someone has been shot from it, up into the bum with a cross-bow. It’s this murder that the bumbling pair Brother Hermitage and Wat the Weaver have to solve.

In the second book, things descend into the toilet, but the humour rises. Definitely a  better and funnier book than the first.