It is a traditional closed circle of suspects mystery, taking place in a fictitious Oxbridge college located in Bletchley about halfway between Cambridge and Oxford on the Varsity Line.

Professor Umpleby, the president of St. Antony's College, is found shot dead in his study one night.

Called in from London to handle the case, Appleby sets to work unravelling the mystery around it while staying at the college.

Despite the attempts of the Dean to suggest otherwise, it is clear that St. Antony's was seething with intellectual jealousy and dislike of the conniving Professor Umpleby.

In the course of his investigations Appleby is clouted round the head, swaps opinions with one of the suspects who is also a celebrated crime writer, and assisted by a group of three students who discover one of the masters, supposedly thousands of miles away, is in fact hiding in disguise near Burford.