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

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.

When Magnum balks at notorious crime boss Osi Shima’s (Eijiro Ozaki) request to find his missing son, Magnum learns he’s been poisoned and has only eight hours to locate Shima’s son to earn the antidote, or else he dies.

When the Dobermans dig up what appears to be a human bone, Magnum and Higgins help Katsumoto investigate the murder of his former mentor.

When Magnum and Higgins get “yacht-jacked,” Higgins is shot and she and Magnum are stranded at sea, struggling to reach land before she bleeds out and the culprits return to finish them off.

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.

Hannah, Magnum's ex and the fugitive responsible for him and his SEAL team brothers being POWs for years, shows up at his home with a gunshot wound, and wanting his help to find her missing CIA father whose life is in danger. Also, Magnum makes an earnest proposition to Higgins for her to become his private investigations partner.

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.

When Rick is asked to assist with a federal investigation of his childhood friend Robbie, Magnum launches his own investigation to see what the Feds really have on him Also, Kumu goes undercover in a retirement community when Higgins is hired to investigate the disappearance of a resident’s life savings.

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.

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 must help his defense attorney girlfriend, Abby Miller, when she realizes that the client she successfully defended in a murder trial is actually guilty. Also, TC confronts Kamekona about stealing his helicopter business.

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.

Magnum and Higgins work a stalking case involving a man with a past in espionage. Also, Ethan asks Higgins to join him on an extended trip for Doctors Without Borders just as Magnum starts to open up to other possibilities.

Magnum and Higgins help Rick when his father figure, Icepick , just out of prison and battling terminal cancer, gets double crossed on one last score. Also, Magnum makes one last bold move to help Higgins stay in the country.

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.

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 is called up from the reserves for a top secret mission, but his friends are stunned when they learn that the mission is a lie and Magnum has been set up.

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.

When Junior is kidnapped as leverage to retrieve the stolen list of undercover CIA agents, and most of Five-0 is rounded up by the CIA to prevent them from interfering, Tani and Quinn ask Magnum and Higgins for their help. The crossover starts on Hawaii Five-0 S10E12 Ihea ‘oe i ka wa a ka ua e loku ana? (Where were you when the rain was pouring?) (I).

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.

A nun hires Magnum and Higgins to investigate a mysterious and large cash donation made to a parishioner undergoing medical treatment at the church. Also, Jin’s new dog walking business takes a dramatic turn, and Rick nervously prepares to reconnect with Suzy.

A journalist hires Magnum to track down his anonymous source after they mysteriously go dark, and Higgins receives a new assignment from MI-6. Also, Rick’s old friend comes to the island, but TC is suspicious of his motives.

Magnum discovers that his ex, who landed him and his friends in a POW camp, is on the island and planing to steal a fortune in gold.

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.

A Christmas Eve ransomware attack on the Honolulu Police Department forces Lia to reveal a family secret to Magnum and Katsumoto.

As Magnum tries to keep his new relationship a secret and handles cases solo while Higgins is away, he is tasked with finding a single mom being hunted by two very dangerous gangs. Also, while Higgins is abroad with Ethan, a misstep forces her to assist an old employer, and Rick gets some bad, but also very, very good news.

A decorated former Navy SEAL who, upon returning home from Afghanistan, repurposes his military skills to become a private investigator in Hawaii.

Magnum and Higgins are hired to find a missing gamer whose online friends believe he might be in trouble. Jin Jeong enlists the help of TC in a treasure hunt after his ex-partner gets out of prison.

Magnum helps Dan, a struggling fisherman and fellow veteran, when his 300-pound tuna worth $350,000 is stolen, and he discovers that the thief needs Magnum's help as well.

Magnum, flooded with memories of his tour in Afghanistan, helps his fallen friend’s brother search for a now-grown Afghan boy who may have been a victim of trafficking.

Magnum and Higgins search for a CEO who has mysteriously vanished. Rick braces for a visit from his wild-child little sister, Ruthie.

Magnum and Higgins agree to help a teenage Amish boy who has traveled to Hawaii in search of his runaway sister. Rick sets out to find TC a date to the Marine Corps Ball.

Magnum and Higgins help an up-and-coming mixed martial arts fighter who is being pressured by a gang to throw an illegal fight. Also, Kumu is arrested for stealing an artifact from a collector that should be returned to its original resting place.

Magnum and Higgins go to work for a dangerous and controversial client. Kumu and Shammy help move TC to a veterans' rehab facility. Rick flirts with a woman who works at the marina.

Magnum and TC go undercover as efficiency experts when a corporate manager is murdered and everyone in the office is a suspect. Also, Rick is curious why Higgins faked an injury to prevent her from investigating the case with Thomas

Magnum and Higgins try to help Zhao, a close friend of Kumu, recover her life savings that was all lost to a scammer. TC becomes increasingly frustrated at the lack of progress in his recovery and pushes everyone away.

Magnum’s Uncle Bernardo visits and reveals a shocking secret about Thomas’ mother. Also, TC asks Higgins for help when he realizes he may have witnessed a potential murder from his helicopter, Higgins decides it’s time to tell Ethan the truth about her past and TC offers Shammy the opportunity to become a pilot.

Magnum takes a case from fellow private investigator Luther Gillis to find the true identity of a man’s comatose fiancée when he learns that she’s had extensive facial surgery.

Magnum and Higgins are hired by a University of Oahu dean to quietly investigate a professor who has been accused of having an inappropriate relationship with a female grad student. TC and Katsumoto take Cade and Dennis on a father-son camping trip.

As their wedding day approaches, Magnum and Higgins help a modern-day Robin Hood who, thinking she was helping a school obtain needed supplies, unknowingly stole illicit drugs. Also, Rick helps a retired soldier with the difficult task of re-entering the work force as a civilian.

Magnum and Higgins investigate the robbery of an elderly man suffering from Alzheimer’s. The ohana tries to help TC overcome a past trauma.

When a married woman asks Magnum and Higgins to find her lover’s killer because she doesn’t want to expose the affair to the police, they find that the victim wasn’t who he claimed to be. Also, Rick visits Icepick, whose health has taken a turn for the worse.

A close friend of Higgins, an art connoisseur who recently hired Magnum to test his security, is murdered, and Thomas is arrested as the main suspect.

A man dying of lymphoma hires Magnum to find his estranged, bone-marrow-compatible brother who turns out to need Magnum’s help as well. Also, Magnum’s case brings back haunted memories for the guys of a past SEAL team mission that went sideways.

While Magnum and Higgins are undercover as a couple on a romantic bus tour working a case, they must switch gears when one of the love birds on the trip is murdered and evidence is quickly deteriorating in the Hawaiian heat.

When an Army ranger goes missing after returning from deployment, Magnum learns of the traumatic news he received upon arriving home and must find him before survivor’s guilt consumes him. Also, Higgins and Ethan solve the case of a missing engagement ring while on a mini-break, and Katsumoto tries spending quality time with his teenage son.

A psychic hires Magnum and Higgins to prevent a murder she claims to have foreseen. Also, Katsumoto questions Kumu when her information is found on recovered stolen jewels that once belonged to the infamous Imelda Marcos, and Higgins struggles with whether or not to tell Ethan the truth about her past.

Magnum and Higgins enlist Katsumoto to go undercover when a chef at a high-end restaurant goes missing. Kumu works with Cade at the Cultural Center, confronting one of America's darker chapters - the internment of Japanese Americans in the wake of Pearl Harbor.

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 and Rick race to find a missing witness who can exonerate an innocent man accused of murder. TC tries to repair his relationship with Mahina after being released from the VA.

TC asks Magnum to take on a case to help acquit the father of one of his young football players, who is accused of murder.

Magnum and Higgins' new partnership is tested when they disagree about being hired by a woman who wants them to recover her $3 million in stolen drug money in order to save her husband's life.

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 Jin learns that an innocent woman is the target of a deadly hit, he asks Magnum and Higgins to help save her.

As Magnum helps a woman find her missing cousin, Sergei, a Russian fugitive, Higgins' and Kumu's lives are put in danger when they get too close to the case.