The gate house - Nelson DeMille (John Sutter #2)

After John Sutter’s aristocratic wife killed her Mafia don lover, John left America and set out in his boat on a journey around the world, eventually settling in London.

After ten long years, John Sutter has come home to the Gold Coast, the stretch of Long Island’s North Shore that once held the greatest concentration of wealth and power in America. Taking up temporary residence in the gate house of Stanhope Hall, John finds himself living round the corner from Susan, who has also returned to Long Island.

But Susan isn’t the only person from John’s past who has re-emerged. Though Frank Bellarosa, infamous Mafia don and Susan’s ex-lover, is long dead, his son, Anthony, is alive and intent on two missions: drawing John back into the violent world of the Bellarosa family, and exacting revenge on his father’s murderer — Susan Sutter.