The new Master, Skullion, the previous Head Porter of the college, is frail after a stroke (or a 'Porterhouse Blue', hence the previous book's title) and the issues surrounding the death of the previous Master, Sir Godber Evans, prompt his widow to instigate a plan to investigate the death through a planted Fellow, backed by a large, anonymous donation to the college.

Meanwhile, the Dean of the college takes it upon himself to visit prosperous Old Porterthusians (previous members of Porterhouse) in the hope that one is willing and able to become Master if and when Skullion cannot continue.

At the same time, the current Bursar is contacted by an American media mogul who seems to be interested in supporting the college without clarifying what it is he wants in return.

Wayne Moriarty, writing for the Edmonton Journal, called Grantchester Grind "a wondrously inventive book that rings as funny as anything Sharpe has written in the past".

He found the books' protagonists to be "typical of all Sharpe characters -- basically good people who opt to cut corners, cheat a little bit, maybe practise modest deceit.