Leys Physical Training College is famous for its excellent discipline and its spectacularly athletic students. Miss Lucy Pym, expert psychologist, is pleased and flattered to be invited to lecture there - even if the Olympian splendour of the students leaves her feeling just a little inadequate.
But a nasty accident spoils the occasion, and suddenly Miss Pym must turn her intellect to the unpleasant suspicion that, among all these healthy young students, there lurks an incurably sick mind...