Magnum and Higgins are on Robin's yacht they picked up for him when they hear a mayday call and respond. However, it's a yacht heist and they're held up by a man with a gun.
Still, Higgins shows some badass moves and fights the guy off, but she falls into the ocean and Magnum jumps in to save her.
The robbers take the boat an leave them in the water but Higgins was shot in the arm. Magnum takes off his shirt to stop the bleeding.
T.C. shares information about his dad with Shammy. T.C.'s dad will be visiting.
Higgins and Magnum are arguing about the best way to get back to land.
Flashback to Magnum arriving at the estate and meeting Higgins and the dogs.
Back to the present where the pair keep swimming as Higgins' arm is still seeping blood.
Kumu lets Rick and TC know that Higgins and Magnum are missing.
Higgins is having issues and has a flashback to another moment with Magnum.
Higgins and Magnum keep swimming.
Rick learns there has been a string of yacht jackings. They head to question a guy who might know something. Of course, Rick knows the club owner and asks to be introduced to Double K.
Double K doesn't want to talk and runs out but Rick chases after and TC knocks him out.
They take the guy to Katsumoto who is not happy but he still wants to stick to the rules.
Katsumoto lets Double K go but they find another way to get information on Double K by taking the guy's cell phone from holding.
Higgins and Magnum run into a bit of trouble on the water. Higgins is having a hard time, but they're near land.
Another flashback to when Magnum was working on Masters' car and Higgins wasn't happy about it.
Magnum and Higgins continue to swim while Rick and gang continue their investigation.
Double K is not happy he was questioned and warns the guys who yacht jacked Higgins and Magnum.
Higgins loses consciousness and Magnum attempts to save her. He gets her and makes it to land but she's still unconscious and not breathing. he performs CPR on her. She finally gets up.
Rick and TC find the hijacked boat but no one on it.
Magnum attempts to make a fire so they can be found but he's not having any luck. Finally, he's successful. She wants to know how he figured out she was MI6 but it was only because Masters told him.
There's a boat on the horizon but it's the bad guys. When they dock, Magnum goes after them while Higgins stays hidden.
Just when they think all hope is lost, TC and Rick arrive.
Magnum and Higgins are relaxing on he yacht, enjoying a beer and talk like old friends.