Past the Shallows is the story of three brothers, Harry, Miles, and Joe Curren, growing up in a small fishing town on Bruny Island off the southeastern coast of Tasmania, Australia. The brothers have had a painful upbringing full of hardships, as their Uncle Nick drowned on the same night that Harry and Miles were involved in a car accident that killed their Mum. Additionally, the boys’ beloved Granddad becomes ill and passes away. After the deaths of their loved ones, the boys are left in the neglectful care of their Dad, an abalone fisherman who has become a violent alcoholic after the loss of his wife and brother-in-law. Joe has previously escaped the abusive household to live with Granddad, but his younger brothers Harry and Miles are left to bear the brunt of Dad’s addiction-fueled cruelty.
As the Curren boys struggle to grow up without loving parents, their brotherhood becomes their support system. Harry, Miles, and Joe each find escape in one another’s company and in nature. Miles is forced to take on the responsibility of working on the fishing boat with Dad and his fishermen Martin and Jeff, as well as taking care of Harry. Miles has a complicated relationship with the water, as he is afraid of diving for abalone but finds solace in surfing with his older brother, Joe. Harry, on the other hand, is petrified of the ocean and escapes into the woods when he is left alone during the long stretches that Dad and Miles spend on the fishing boat. He inadvertently befriends the local hermit George Fuller and his dog Jake, finding the love and understanding in his relationship with George he lacks from his own abusive father.
Joe, who works as a carpenter, is unable to handle the pressure of being a surrogate father figure for his two younger brothers, despite his love for them, and spends years building a boat in hopes of sailing away from Bruny Island. After the boys’ Aunty Jean contests Granddad’s will and reclaims the house that he left for Joe, the boys reluctantly clear out Granddad’s belongings. Miles discovers that their grandfather kept the wreckage of Mum’s car from the night of the accident and finds a shark tooth necklace between the car seats. The mysterious tooth haunts Miles as he tries to place its origin, wondering who could have left it in Mum’s car. Once Granddad’s house is packed, Joe’s dream becomes a reality as he bittersweetly leaves his two younger brothers to live on his boat and travel the world.
In Joe’s absence, Dad’s behavior quickly spirals out of control. After Martin is injured and has to take a leave from fishing, Jeff convinces Dad to begin poaching abalone in protected waters in order to yield a more fruitful harvest, a decision that catches the attention of the Fisheries authorities and places Dad’s livelihood in jeopardy. Dad’s drinking also becomes worse, as he often abandons Miles and Harry to spend his nights at the local pub. In the midst of a two-day alcohol bender, Dad and Jeff lash out violently at Harry and Miles, as they force Harry to drink whiskey and Jeff slams Miles’s head into a coffee table. After this horrific incident, the boys run away from home and end up at George Fuller’s house. Miles ultimately decides to leave Harry with his schoolmate Stuart Phillips, where he knows his little brother will be safe.
Miles goes back to live with Dad, and they end up nearly running into Harry in the middle of the road one night, as he emerges from the woods after a visit to George’s shack. Dad is livid, and they bring Harry back to live at the house with them. One morning soon after, Dad inexplicably wakes up Harry and Miles before dawn and forces the boys to come out on the fishing boat despite the violent winter storm that is brewing. As Dad and Jeff dive for abalone, Miles does his best to calm Harry’s fear of the water but is interrupted when he realizes that the boat’s engine has stopped and cut off Dad and Jeff’s air supply.
Dad and Jeff eventually make it back to the surface, where Dad is furious with Miles and unfairly blames him for the engine failure. He vengefully holds Miles underwater until Harry kicks his father and forces him to release Miles. Dad’s ire then switches to Harry, who attempts to call for help on the boat radio. As he grabs and furiously shakes the little boy, Dad notices the shark tooth necklace that Miles had given Harry that morning to wear for good luck. Recognizing it as having belonged to Uncle Nick, he grows even more furious, implying that Harry is actually Nick’s biological son and throwing him overboard into the bitterly cold water. As Miles fights to jump in after his little brother, Dad restrains him and confesses that Mum and Uncle Nick were having an affair and that Nick did not drown. Rather, he had been in the car with Mum, Harry, and Miles on the night of the accident and Dad removed his body from the scene in hopes of saving their family from the humiliation of the infidelity.
After this harrowing revelation, Dad finally lets Miles go and Miles springs into the water after Harry. He tries desperately to save him and swim for land but is unable to find his way amidst the violent storm waves crashing around them. The brothers tread water for as long as possible until Miles eventually slips away into a hypothermic delirium and loses consciousness. He wakes up in the hospital to find that he survived, and that Joe has come back to stay at his bedside. Miles is thrown into a state of hysterical shock when Joe tells him that Harry drowned to death.
Miles and Joe are utterly grief-stricken at the tragic death of their little brother. Dad has seemingly fled town in shame and the brothers are at a loss of what to do or where to go. After living on Joe’s boat docked near Granddad’s house for a short time, they decide to leave Bruny Island. Not wanting to endure the platitudes of Aunty Jean and other relatives at Harry’s funeral, Miles and Joe decide to have their own ceremony with George and Jake at the sand dunes of Cloudy Bay. After burying Harry’s beloved collection of beach treasures, the brothers say goodbye to George, who had become the Harry’s dearest companion before his death. He returns the shark tooth necklace that Miles had given to Harry for good luck, and Miles realizes that George was the one who found Harry’s body. The novel ends as Miles and Joe board Joe’s boat and sail away from Bruny Island, devastated yet hopeful as they look ahead to the future and embark on a new path.
