Snow by John Banville (St. John Strafford #2)

'The body is in the library,' Colonel Osborne said. 'Come this way.'
Following the discovery of the body of a highly respected parish priest at Ballyglass House - the Co. Wexford family seat of the aristocratic, secretive Osborne family - Detective Inspector St. John Strafford is called in from Dublin to investigate.
Strafford faces obstruction from all angles, but carries on determinedly in his pursuit of the murderer. However, as the snow continues to fall over this ever-expanding mystery, the people of Ballyglass are equally determined to keep their secrets.