How many bodies can one dog find?

Another day in the life of Detective Inspector Colin Knowles and another murder. Bingo the retriever has been finding bodies again. This time someone left a sword in the back of Edward Pritchard in the grounds of a 700-year old monastery. 

Pritchard used to work at the nearby stately home, Manton Rempville Hall, as a gardener, although all he seemed to cultivate was reasons for people not to like him. As luck would have it, there's a house party at the hall so there are plenty of suspects. People are unwilling to give up their secrets easily and Knowles has to dig to find answers. 
Knowles inspects the libraries, the studies, and the not-so-secret passage of this old hall in an attempt to find out who murdered Pritchard. He's in a race against fate, because he suspects the killer will strike again. 
Bells, owls, and ironic topiary all play a part in his investigation as Knowles slowly weeds out the suspects. But will he be in time to stop further deaths happening...?