Magnum and Higgins are sent on a deadly mission inside a high security correctional center when a ruthless criminal abducts Katsumoto and his ex-wife, Beth.

An armed hit team lays siege to Robin's Nest. TC is badly injured while Rick fights for his life. Mid Season Finale

Katsumoto's hearing date has arrived and he will learn if his career in law enforcement is over for good or not. Magnum and Higgins are hired to investigate a man their client believes committed murder. Rick's suspicions grow on their relationship.

Kumu and Higgins are in danger when Robin's Nest is under siege by mercenaries storming the estate in order to find out the true identity of the White Knight, Robin's muse and literary hero. Also, Rick and T.C. helps one of Rick's employees when his car is stolen, and Higgins finally gives Magnum an answer about if she'll become his partner.

As Magnum, Higgins and TC try to pull one over on a customs agent to get Higgins a green card, armed gunmen suddenly storm the federal building and start taking hostages.

Magnum and Higgins take on a case that sends Higgins inside a psychiatric hospital. Katsumoto and his son, Dennis, head to the mainland to look at colleges, but their trip takes a harrowing turn when a run-in with a local turns ugly.

Higgins’ therapist hires her to look into why one of her teenage patients died of suicide.

When Magnum and Higgins are hired by an anxious groom to look into his bride-to-be on the eve of their wedding, what they think is a simple case of cold feet turns into a web of lies and a life-or-death situation for Higgins. Also, TC makes a touching decision on how to help Cade.

Magnum starts following Higgins to discover what she’s been hiding, as she’s secretly assigned to infiltrate a group threatening to take down MI-6. Rick struggles after an explosion takes the life of someone important to him.

Magnum and Higgins weigh the risks of pursuing a relationship. Rick juggles being a new father and running La Mariana. Katsumoto tries to figure out his next move.

Katsumoto takes a job providing security for a chart-topping K-pop star. Higgins and Rick find themselves in peril while trying to help Rick's friend. Magnum harbors suspicions about Capt. Greene's death.

When Katsumoto suspects that one of his fellow cops is dirty and has stolen evidence, he begrudgingly asks Magnum and Higgins for help. Also, Rick and TC help Los Angeles Rams defensive tackle Aaron Donald when his tablet, that contains the Rams’ playbook is stolen.

When a woman hires Magnum and Higgins to locate a man she met briefly at a coffee shop and felt a spark with, they learn that he is hiding a big secret. Also, Higgins keeps a secret of her own after she has a romantic dream about Magnum.

When Hawaii Supreme Court nominee Judge Rachel Park is being blackmailed, she hires Magnum and Higgins who go to extraordinary lengths to help her out. Also, with the pressure of fatherhood looming, Rick suggests changes to make La Mariana more profitable, but TC and Kumo aren’t swayed.

Magnum goes to extreme lengths to uncover the truth about a crime that may have involved his dear deceased friend, Nuzo.

A disoriented man hires Magnum and Higgins to investigate a crime he doesn’t remember after he woke up on the beach covered in blood. Also, T.C. is taken aback when Cade’s biological grandmother makes a surprise visit, and Rick’s feelings for Suzy grow stronger as they prepare for the birth of their first child.

Magnum and Higgins go undercover as lifeguards in order to solve a murder. Jin Jeong wins a storage unit auction and enlists the help of Rick and TC upon finding a stolen military medal.

Magnum and Rick make a shocking discovery in the Capt. Greene case. Higgins and TC head to Maui to help an eccentric billionaire find the owner of a pesky drone that has been harassing him. Shammy helps Kumu after an incident occurs at La Mariana.

After a high-stakes homicide case falls apart at trial, Katsumoto asks Magnum to help him stop a killer from walking free. Higgins helps Jin Jeong with a mystery of his own.

While Magnum helps out his friend Russell Harlan and temporarily works as the head of a hotel’s security, he investigates the death of a guest who was thrown from her room’s balcony while working on a secret investigation of her own. Also, Icepick is released from jail and is trying to keep a secret from Rick.

As a major hurricane hits the Island, Magnum and his friends find shelter inside La Mariana, along with two armed killers also escaping the dangerous storm. Also, Rick must confess to TC that he let the insurance lapse on the bar.

When Higgins is abducted, Magnum discovers its retaliation related to one of his first cases on the Island, and he, Rick and TC must break out an ex-client from prison in order to save her.

When a Marine Corps vet’s SUV is stolen with her service dog inside, Magnum and Higgins must find the car, the dog and the car thief who they believe may be an escaped kidnapping victim. Also, when TC is sued by a disgruntled customer, he asks Rick and Jin to help prove that he’s being scammed.

Magnum, Higgins and Rick go undercover at a ritzy country club when a young caddie is fired after being accused of stealing a member’s golf clubs. Also, Jin’s niece, unaware of her uncle’s shady past, asks him to speak at her school.

Shammy asks Magnum and Higgins to locate his missing friend, a homeless veteran. Also, T.C. tries to get Cade to return to school, but quickly learns it’s not that simple.