Debts of Dishonor — Jill Paton Walsh

Imogen Quy--rhymes with why--is the witty, compassionate, and relentlessly inquisitive college nurse at St. Agatha's College, Cambridge University. Unfortunately, St. Agatha's has seen better days: Its financial affairs are in shambles, and the school is teetering on the verge of bankruptcy.
That is, until billionaire financier and St. Agatha's College alum Sir Julius Farran decides to pay his alma mater a visit. Things are looking up for St. Agatha's....but when Sir Julius suddenly dies in questionable circumstances, St. Agatha's is in danger of closing forever. A nurse is a natural receiver of confidences, and Imogen soon learns that Sir Julius had far more enemies than friends. Her curiosity is initially piqued, but soon turns to alarm when Julius's equally unpleasant son-in-law is found murdered. The case takes on particular urgency because Imogen's former flame, Andrew Duncombe, had been working as Sir Julius's right-hand man. Imogen must work what out really happened before Andrew is implicated in the murders--or becomes the next victim.