An old man is found sitting on a bench in front of an abandoned gas station and left all alone in a depressed and destitute state. Forwarding to his past, he is Jerry Black, an aging Reno, Nevada, police detective’s last day of work, it's his retirement. Sitting in a chair in his office, he is engaged in recalling
memories of his work life. When he returns on the day he has been dragged to attend a retirement party hosted by his department, Captain Pollack gifts Jerry with tickets to a fishing vacation in Mexico as a gift. Cut to the other scene, a boy on his bike with snow riding gears makes a pit stop due to the bike's malfunction. He notices a man running suspiciously towards his red truck after noticing the boy. The boy follows the suspicious man’s lead to find the reason behind his move. And the boy ends up discovering the dead body of a young girl, Ginny Larsen. Ginny Larsen, an approximately 7-8 yrs old child, was murdered and discovered during Jerry’s retirement party. Jerry decides to go to the crime scene with another detective, Stan Krolak.
Jerry informs Ginny's parents of the bad news, and the mother, Margaret Larsen, makes Jerry swear on a cross made by their daughter that he will find the killer. The next day, a suspect, Toby Jay Wadenah, a Native American man with an intellectual disability, was also the suspicious man who was running from where the crime was discovered. Stan takes advantage of Toby's mental illness by convincing him that he murdered Ginny. Toby steals a deputy's gun and commits suicide after confessing to doing so. An autopsy on Ginny reveals that she had consumed chocolate before her death; wrappers discovered in Toby's truck strengthen the case that he murdered the young girl, and the case is closed, despite Jerry's suspicions.
Jerry refuses to go to Mexico and misses his flight because he is adamant about finding the murderer. Instead, he pays a visit to Ginny's grandmother, Annalise Hansen, who tells him about the many stories she and Ginny used to read, including one about an angel who descends from Heaven to fly a deceased child over all the places they loved in life before delivering them to God. Jerry then pays a visit to one of Ginny's friends, Becky Fiske, who reveals that she was friends with a man she referred to as "The Giant," who gave her a porcupine whom he met on the mountain shortly before being murdered. Becky also mentions that he referred to himself as “a wizard”. Becky says that Ginny has drawn a picture of him, and that has been kept in the school. Jerry discovers a drawing of "The Giant" by Ginny, but it
does not resemble Toby and depicts a black wagon rather than the red truck driven by Toby.
Jerry approaches Stan and asks him to reopen the case. Stan refuses but provides Jerry with more information about similar cases in the area. Jerry's investigations turn up three unsolved local cases with the same M.O. as Ginny's, but which Toby could not have committed because he was in prison at the time. Jerry meets another detective who was in charge of those previous murders that happened years ago, which also bore the same resemblance to Ginny’s case. As part of the investigation, Jerry then presents his research, the clues that he got from Ginny's drawing, and the resemblances of previous cases to Captain Pollack and Stan, who are skeptical.
As a single man, Jerry likes to investigate more about the case to find the murderer. He moves close to the place where the murders happened. He notices a gas station near the center of the case while fishing. Jerry moves into the house behind the station after purchasing it and meets Lori, a local waitress/bartender, and her daughter, Chrissy. He started to take care of the gas station and suspected all the black wagons that entered the station for gas filling. He then takes Ginny’s drawing to a doctor, who describes the person who drew the art, Jerry was thinking that he might get some clues to find the murderer. But the doctor points out that this drawing could be the imagination of a 7 yr old girl and nothing more than that. She also mentions that, according to the resemblance of the cases, another murder might happen within certain months or maybe a year.
Jerry takes Lori and Chrissy to a market area, where he finds a shop selling porcupine toys. Enquiring about the shopkeeper, Jerry gets the address of that porcupine seller and visits their home. He meets an old lady (the seller) and notices her son coming in a black Wagon, which makes Jerry one of the strong suspects. On the other side, he also develops feelings for Chrissy and befriends the small family. Lori arrives at Jerry's house one night, bruised and battered, and explains that her ex (who has a restraining order) attacked her. Jerry suggests that Lori and Chrissy temporarily move in with him out of concern for their safety; she agrees. Jerry gradually develops a fatherly relationship with Chrissy and even starts a romance with Lori.
Gary Jackson, a local pastor, pays Chrissy a visit outside the station one day. Jerry suspects Jackson of being Ginny's murderer after inviting Chrissy to his church. Jerry rushes to the church after Jackson picks her up one day while he is fishing, only to discover that it was just a close call and that Jackson is not the murderer.
Meanwhile, Chrissy begins meeting with a man who drives a black car with a toy porcupine hanging on the rear mirror; porcupines were another aspect of Ginny's drawing that irritated Jerry. Chrissy tells Jerry at bedtime that she met a "wizard" who gave her porcupine candies and told her not to tell her parents about their correspondence. Chrissy informs Jerry of a meeting between her and the "wizard" the following day. Jerry stages an operation with Stan's assistance to catch the killer, using Chrissy as bait. Stan brought the whole team, and they were waiting on the riverside along with Jerry to catch the murderer. However, while they are waiting for him, the "wizard" is killed in a car accident. Hours later, Stan gives up the mission, considering Jerry was mentally running down because of Ginny’s case. Before he leaves, Stan informs Lori what has happened. Jerry is confronted angrily by her and walks away, taking Chrissy along with her.
Jerry later sits alone on a bench in front of the demolished gas station. Jerry ends up alone, despondent, destitute, and drunk, mumbling to himself that the killer is still out there, unaware that he is dead.
