Why did Sir Julius Farran die?

Hoping to attract a generous endowment, St Agatha’s College, Cambridge, invites the fabulously wealthy Sir Julius Farran to dine. The evening is a disaster for everyone except the college nurse, Imogen Quy, who Farran invites her to come and work for him.

Imogen declines, but when Farran dies, suddenly and shockingly, she has to investigate. His death has left a large hole in his company accounts that could mean financial ruin for St Agatha’s. To save her beloved college, Imogen starts to cast her cool eye over the financier’s heirs, employees and enemies.

What is right about the death of Sir Julius? What is wrong about it? And above all, why did it happen?