A police detective investigates the disturbing murder of a young family in a mostly abandoned housing development. Detective Mike "Scorcher" Kennedy, a hardboiled police detective who likes everything to go by the book, is called to investigate a tragic murder. Scorcher and his rookie partner, Richie Curran arrive in Brianstown, a housing "estate," or development in the suburbs of Dublin. The detectives find the area disturbing. Ireland is experiencing a sudden economic depression after a decade or so of explosive and optimistic growth. Brianstown, a high-end seaside community, is in terrible repair because the budget for building ran out before the estate was finished, and because not nearly enough buyers showed up.
The Spain family was attacked in their home, which is situated in a particularly bleak section of the estate and surrounded by empty homes. Pat and Jenny Spain were found stabbed in their kitchen and their young son and daughter were found smothered to death in their beds. A call to the police appeared to have been placed from the home. Jenny is the only family member to survive the attack but remains in critical condition, at first unable to speak to the police.
Scorcher finds himself more shaken by the crime than he expected because it reminds him of a terrible incident from his childhood. Back then, Scorcher's mother committed suicide. Scorcher's younger sister never recovered from the tragedy, suffers from delusional bouts of mental illness, and drifts in and out of his life.
Scorcher and Richie find some very strange things in the Spain home. Holes have been cut in many of the walls and baby monitors and video cameras have been placed in the house. The detectives' first theory is that the couple was afraid of break ins or being menaced. Scorcher goes through Pat Spain's internet activity and finds that he spent a lot of his time on chat boards, asking questions about vermin. His posts indicate that he had been hearing some sort of animal within the walls of his home. The detectives also look into the family's financial records and see a downward spiral that began with Pat losing his job. Bills went unpaid and while at first Pat made an intense effort to find new work, it looks like he eventually gave up. The more time he spent at home, the more focused he became on the animal in the walls. The detectives begin to believe that Pat Spain was paranoid and depressed, and eventually snapped under pressure and attempted to kill his family, then stabbed himself to death.
A man named Conor watches the detectives work. Conor is also out of work and has lost his home. He is an old school friend of the Spains and in his moment of desperation, moved into an empty, unfinished home with a view of the Spains'. A young boy alerts the detectives to Conor's presence and he is brought in for questioning. Conor idealizes his memories of the time he spent with Pat and especially Jenny in their youth. He had watched the family through their windows with binoculars, gaining solace from their happy life together. When he noticed a change in mood after Pat lost his job, he did not like seeing Jenny so sad. He hoped to subtly cheer her up, so he snuck into the Spain home and left a little pin-on button that he had saved as a souvenir from a long ago day at the beach, on the kitchen counter. He had hoped it would trigger a happy memory for Jenny too.
In flashback we see that finding this button had the opposite of the intended effect on Jenny. Knowing she once owned an identical button and that she had not placed it on the counter, she began to feel that she was losing control of her own mind and her anxieties about her family's future only increased.
Conor confesses to the crime but something does not sit right with Scorcher. Jenny regains consciousness and is able to answer questions/ Scorcher feels she is not being forthcoming. When Richie finds a fingernail that looks like it belongs to Jenny, in the children's room, Scorcher takes advantage of Richie's improper collection of the evidence and does not add it to the case file. He realizes he has done this because his instincts say Jenny is the guilty one, but he can't stand the thought of her being charged. Scorcher and Richie talk about this and Richie says it would be better if Jenny was indeed arrested because if she did commit the crime and failed to annihilate herself, she is most likely still a danger to herself. Scorcher thinks it would be best to let her commit suicide when she gets out of the hospital because she will never be able to live with what she has done.
The detectives continue to look at Pat's internet activities and a picture of him as a seriously disturbed man emerges. He has obviously spent whole days and nights online writing about the sounds the animal makes, and purchasing dangerous traps which he set up in the house.
Scorcher pressures Conor to tell the truth about the night of the murder and Conor does, admitting that he was watching the house that night and is a witness to what happened. He observed Pat holding one hand through a hole in the wall, apparently to entice the possibly imaginary animal to bite him. In his other hand, Pat held a large knife, apparently planning to kill the animal when it came. Instead, Jenny found Pat like this, wrestled the knife from his grip and stabbed him. She had obviously decided to put her entire family out of their misery. Horrified, Conor ran to the Spain house and found Jenny in a desperate state, having terribly injured, but not killed her husband. She begged Conor to finish the job. Conor ran upstairs to check on the kids and found that Jenny had already killed them. He returned downstairs and tried to do as Jenny asked, seeing no other solution. But, he confesses, he has always loved Jenny and could not bring himself to kill her, only to critically injure her.
Scorcher returns to the hospital and speaks to Jenny again. She seems ruined as a person but relieved that Scorcher does not seem to know the truth. As the story ends, Scorcher feels himself ruined as well. The pain from his own childhood continues to this day, and now he has hidden evidence, going against everything he stands for, and feels he must walk away from his career. He feels little hope for anyone or anything in Ireland. We never really know whether the animal was entirely imaginary.
Best part of story, including ending:
I really liked the story of Broken Harbor because, although the plot was rather messy, I loved the spooky setting of the near-empty housing estate and the window into Ireland in this particular time.
Best scene in story:
My favorite scene was when Conor tells Scorcher what really happened the night of the murders, because I finally got answers to frustrating questions.
Opinion about the main character:
I disliked Detective Mike "Scorcher" because he was a familiar type of central-casting hard-boiled detective, and that is not a voice I enjoy.