Grace Hanadarko is an Oklahoma City police detective with an alcohol problem and a self-destructive lifestyle. After she hits a man with her car while driving drunk, she asks God for help and an angel named Earl appears. Earl wants to help her find the right path of life again, but it is going to be a hard piece of work for both of them.

Grace and her team investigate the murder of an oilman. Meanwhile, Ham discovers Grace's romantic past with Butch Stillwater, which puts a strain on their relationship. Grace sets out to prove her courage by challenging Earl to a wrestling match.

Grace and her team investigate the murder of a manager of a sleazy local motel. The investigation eventually leads to a maid, who claims the victim was trying to rape her. Complications arise when a local priest offers her the right of sanctuary. Meanwhile, Grace begins to accept Earl's presence in her life.

A 17-year-old devout Christian comes under attack just days before he’s scheduled to testify in a murder trial. In order to ensure his safety, Grace allows him to move in with her. But Grace can only handle so much preaching, so she ropes the guys into helping her watch over him. Grace gets pissed when Earl uses Leon Cooley and her nephew, Clay, to get her attention.

Grace and Ham play cops and robbers with toy guns. Grace’s favorite Aunt Cathy comes to town – has a run in with Earl, clashes with Betty – and reveals some shocking news. But first-- Rhetta, Grace, and Aunt Cathy get drunk and remember old times. Meanwhile, cattle tycoon Alvin Green’s world begins to crumble after his lucky bull statue is stolen. He insists Major Crimes take the case. When Grace’s father has a fire station named after him, Grace’s family comes together for the dedication ceremony. Henry’s cat dies and Grace comforts him the only way she knows how.

The death of an alleged call girl in a flight attendant’s uniform leads Grace and the guys to investigate a notorious Oklahoma crime family. Grace is finally confronted by Ham’s wife about the affair. A financially-strapped Rhetta gets excited about making two grand as an expert witness. And Grace and Rhetta hatch a secret plan for Rhetta to meet Earl.

Grace and the guys investigate the murder of a “crispy critter” in the Oklahoma countryside and Bobby soon discovers the deceased was one of his mentees. Grace enlists the help of her Native American grandfather, “Geepaw,” to help with the case, but is shocked when she sees how quickly his health is deteriorating. Grace and her sister, Paige, fight over many things, including Geepaw’s future in a nursing home. Earl tries to make Grace realize the importance of family… and Grace and Butch rekindle their passion.

During the raid on a killer's house, Grace gets shot and almost dies, while another policeman isn't as lucky as her and gets shot to death. Meanwhile, Leon Cooley has to deal with his ex-wife marrying another man, who might adopt his son.

A crime from 11 years ago is on Grace's thoughts due to a new case.

3 children are killed in a bus accident and Grace's investigation is interrupted by bad weather as tornadoes rip through the city.

A home for the mentally challenged is the target area of investigation when a robbery occurs involving a man with Down Syndrome.

A defense attorney from Los Angeles comes to town for a murder trial and his presence may influence the team in professional and personal areas of their lives.

A photo of Grace's sister, Paige, is found in a burning car.

Grace struggles with what she should do about father Murphy. Off duty from calling in sick she winds up capturing number six on the FBI's most wanted list while meeting Gretta. After Grace brings in father Murphy he winds up dead and she's suspected.

Grace is called to the crime scene where there is blood everywhere but no body; Ham and his wife separate; a ketchup and mustard incident becomes a running joke around the squad room.

The squad's evidence supervisor is found dead in a bathroom stall at the local cop hang-out; Ham's brother comes to visit before being deployed; Grace and Leon dream about each other.

A mother goes missing; Clay joins the OCPD Explorers program against his father's wishes and confronts Ham about his affair with Grace; Butch becomes the target of a stalker.

A large stash of money is found in Grace's car when the door is knocked off by a drunken driver; Ham's little brother disappears in Afghanistan.

A woman is brutally murdered and her son is abducted; the squad works frantically to find the missing boy; Bobby surprises the squad and his family by going under cover; Ham continues to struggle with his personal loss.

A young Mexican woman dies at the hospital after being dropped off by a known white supremacist; Ham continues to struggle.

The squad tracks down a serial killer who has been mutilating women; Ham is temporarily partnered with Butch during Bobby's absence; Earl tries to persuade Grace to help Leon.

A teenage girl dies at a school friend's party that Grace's niece was at; Grace has a new partner; Johnny tries to learn more about Earl.

The team blows Bobby's cover when they investigate a murder; Grace has suspicions about Abby; Rhetta and Johnny meet with Leon.

The team investigates a woman's death, while Grace seems captivated by the prime suspect, a high-profile architect and her unusual sex life. Meanwhile, Grace and Ham partner up once again, with hopes that their romance will be rekindled by the union. Elsewhere, Bobby's undercover case leads to an explosive conclusion, and Clay forms a bond with a young kid.

Grace takes on an investigation when a jogger with a intricate love life is found dead. Meanwhile, Clay's father and a new bartender from a local joint begin dating, and Grace worried that this will have a negative impact on Clay. Leon gets a visit from a former high school classmate.

Doug and Maggie's romance has flourished so much that they set their wedding date, but the date may be put on hold when Maggie is attacked by an unknown predator. Meanwhile, Johnny and Rhetta try passionately to save Leon from his upcoming execution by starting a petition. And young Clay continues bonding with Leon's son.

As the squad investigates a fatal shooting by an elderly woman, Leon Cooley’s execution date arrives. Grace, who has discovered that Leon once helped her sister and was invited to a family birthday party, struggles with whether or not to lend a hand towards stopping the execution. Grace also finds a connection with a young woman, who may also be getting visits from Earl. And Ham’s divorce is finalized, which he hopes will make things between him and Grace more permanent.

Grace ends up in the middle of what could be a plot by an anti-government group linked to the recent death of a police officer, as she reaches out to Neely, the young drug addict who shares visions of Earl. Grace's clumsy, off-the-books investigation causes Neely to become injured. Meanwhile, Grace and ham get caught in a compromising position, and Butch makes a surprise announcement.

Grace and her crew investigate the unusual suicide of a court reporter, and conclude the crime was staged. Elsewhere, Grace tries forming a bond with Neely, despite the fragile physical state of the young drug abuser; and Rhetta is close to losing something very special to her.

A bomb explodes at the church run by Grace's brother,, making the case personal for her. Meanwhile, Rhetta is haunted by family problems, causing her to search for a family time capsule she and Grace buried as children. And, Grace keeps a watch at Neely's bedside.

The team is focused on a series of brutal home break-ins, but the latest one seems different than the others. Meanwhile, Matthew, a fellow angel of Earl's, is having trouble saving souls, and hones in on Earl's space.

During a case that puts Grace’s spirituality to the test, the squad investigates the murder of a Hasidic Jew whose body is found near a herd of dead cows. Meanwhile, Grace tries to connect with Neely, and Ham’s sister-in-law, Amanda, struggles to get over the death of her husband.

Grace pursues a rape and kidnapping suspect on foot and disappears, possible as a victim herself. But nothing concerning this seems to make sense, including how Earl works the works the investigation. Ham and Rhetta must team up to find Grace before a shocking ending which will leave a lasting impression on the series.

The squad investigates the death of a 99-year-old man who has been shot in the head sitting in his home. The case, which resembles a crime that happened in Tulsa three years ago, offers Grace and Perry an opportunity to utilize their expertise in gambling-related crimes from the vice days.  It also gives Bobby a chance to reconnect with his dad and Ham a chance to connect with a kindred spirit. But Grace’s attention is drawn towards Rhetta when she learns something unexpected about Ronnie.

Butch's reporter girlfriend covers the bizarre slaying of a drug company whistle blower in hopes for a big national scoop. Elsewhere, Grace's brother believes his neighbor has a dead body inside his home; and Johnny hopes to finally meet Grace's last-chance angel.

The squad investigates the death of a parole officer with a secret life, while Grace and her brother Johnny finally track down Neely, the young addict who shares visions of Earl. And Rhetta decides to make some personal changes in the wake of her troubles at home.

Summer finale. A prominent doctor fatally wounds an intruder in his house, but Grace feels the doctor's story isn't exact. Ham breaks some interesting news to Grace, and Earl tells her she will need to help Neely.

In the immediate aftermath of Grace and Neely’s survived fall from the top of a building, Grace, now known as “Angel Cop” by the city, decides to have it out with God once and for all. But a mysterious stranger might have something to say about that. Ham struggles with his father over the fact that Ham is now dating his dead brother’s widow. And the squad investigates a deadly mauling by a dog.

As Grace deals with the aftermath of her dramatic fall from a building with Neely, she also struggles with the impending death of her grandfather, GeePaw (guest star August Schellenberg). Meanwhile the squad investigates a double homicide involving a water dispute between two ranchers, and Rhetta discovers a secret about her daughter.

A friend of Grace's doesn't want any help in the possible murder of her husband. The squad has little time to waste in trying to track down and a missing person with brain damage. Grace tries to find out exactly when Earl began following her.

Grace gets to see a new side of her nephew when a rock band is related to the murder case. Neely lives next door to Grace and begins withdrawal with help from Earl. Rhetta continues where she left off with Ronnie.

Grace may be able to tell God all the things she has done through her life because of her bond with Earl.

Everybody can't figure out why Capt. Perry seems to be on an edge all the time. Rhetta and Ronnie learn to communicate better since the start of their relationship with Johnny.

Grace must cope with survivor's guilt after a fall off a building. Captain Perry has an announcement that could change everything. The squad looks into a murder mystery.

Grace has trouble dealing with a food issue and doesn't go to anybody for help to deal with it. Neely's having trouble when her drug problem spirals out of control. A friend of Butch's needs help getting out of a tough situation.

Grace returns to Oklahoma City long rejuvenated and with a new perspective on how to deal with crime. Her family is still trying to grasp with exactly what happened.