All Our Yesterdays

This is a book by Robert Parker that is not one of his well-known series (Spenser, Jesse Stone, Cole & Hitch, or Sunny Randall) but a stand-alone that looks at three generations of two families: the Sheridans and the Winslows. It is only when  3rd generation Christopher Sheridan is threatened with the loss of his long-term love, Grace Winslow, that it appears the self-destructive cycle of marrying the wrong woman for the wrong reason might be broken. Christropher not only breaks out of his safe ivory tower life as a professor of criminology at Harvard by accepting a special prosecutor's job tasked with investigating gang warfare, but he delves into his history by going back to his roots in Dublin where the trouble all began.
Chris' grandfather, Conn Sheridan, was a soldier with the IRA and became involved with a sympahtetic American woman, Hadley Winslow, during "the Troubles." When he was ordered to leave Dublin, he begged her to come with him, but she had seen their affair as no more than an adventurous fling and had no intention of abandoning her upper class life. She betrayed him to the British and he was put in jail, sentenced to hang. With the help of his colleagues in the IRA, he escaped and went overseas to Boston--not coincidentally, where Hadley was from. He became a cop, then a detective, and then a case came his way that brought Hadley not only back into his life, but also at his mercy.
This is also the story of Gus, Conn's son and Chris' father, who became a police chief, taking money from the gangs. He loves Chris to distraction and would and did do anything for him. But he never found a woman to love until he met the wife of Hadley's son, who was also the mother of Grace, Chris' partner. Yep, the three generations of Winslows had all been romantically involved with the three generations of Sheridans, mostly with disastrous consequences. But everyone is freed from their obsessions in the end--one way or another. As usual, Parker does an outstanding job of creating characters through dialogue even more than action. It is a long'ish book (nearly 500 pages) spanning several decades, but eminently readable.