Longworth teams up with his old partner, Detective Samantha Harper to track a serial killer from Chicago and Callie can't help but notice the obvious chemistry between them. Manus asks Callie to work as a forensic nurse for the FDLE.

An 8-year old's slumber party becomes a crime scene. Callie accepts Manus' offer and joins the FDLE as a forensic nurse. Jim's investigation into the death of a Navy recruiter leads to the ex-wife's boyfriend and her missing baby

A stolen car and a body have Jim investigating some NASCAR drivers. After Ray is attacked, Callie must consider the option of witness protection.

Longworth's investigation of a man beaten to death in a truck stop restroom finds clues leading to a luxury rehab center. In addition to the crime, Carlo is dealing with his daughter's Quinceañera and a former colleague who needs his help. Callie and Jeff are struggling with Ray's absence

Longworth investigates a murder in Gibtown, a community populated with human sideshow descendants, and everyone is a suspect. Jim and Callie try to figure out the exact meaning of their relationship.

The murder of a Haitian doctor leads Longworth and the FDLE to a pill mill and a corrupt doctor's office. Addicts have been paying big money for pain medication all of which leads to a long list of suspects.

The FDLE enters the battle between good and evil when a Pentecostal preacher is found dead in a snake pit. Longworth's investigation into the House of God eventually leads him to the Big House and a fatal case of mistaken identity. Meanwhile, Sam's departure has Callie questioning her own relationship with Longworth.

Jeff's mentor, the high school soccer coach, is found shot dead on campus.

When body parts of a Coast Guard Reservist are found in the belly of a poached wild boar, Longworth hunts the killer into the depths of the Glades. Meanwhile, Callie and Longworth decide to push the restart button on their romantic relationship.

A body is found at a popular beachside bar with a large diamond ring in his pocket. Longworth sifts through the sands of the various characters at the bar, revealing a complicated love triange that may have ended in murder. Meanwhile, Callie has some news for Longworth that will change everything.

An Ernest Hemingway look-alike is discovered adrift under a glass bottom boat with a bullet hole in his head during a "Hemingway Days" booze cruise. Turns out, the victim might have gotten caught in the middle of a family feud between bootleggers. Meanwhile, an old romance from Callie's past reappears and drops a bombshell, one that could seriously affect her relationship with Jim, the FDLE, and the hospital.

In the thrilling season finale, Callie's hospital is on lockdown when a pair of ex-con brothers take hostages. Longworth and Callie work together to ensure the safety of the hostages, but things take a turn for the worst leaving Longworth to defuse the situation before it explodes.