Friendship is a lot like the ocean — it ebbs and flows, is sometimes rough and stormy, yet when it is calm it can soothe and nurture your soul. One of the strongest elements of “Magnum P.I.” is the friendship shared between Magnum (Jay Hernandez), Rick (Zachary Knighton), and T.C. (Stephen Hill). Their bond is a brotherhood born in combat and strengthened while they were POWs in Afghanistan.

In this week’s episode, “Sudden Death,” written by David Fury and directed by David Grossman, Magnum’s friendship with T.C. is put to the test when T.C. asks him to look into the murder charge against the father of one of his football players. T.C. coaches a youth football team and he has a soft spot for his star player, Makoa Iona (Zion Junk), whose childhood seems to mirror his own. Makoa’s father, Hani (Sam Puefua), has taken a downward spiral after the death of Makoa’s mother, and T.C. understands what it’s like to be raised by a single father who sometimes has trouble with the law.

SUDDEN DEATH

In a sport or game, sudden death is when the regular game has ended and each team has a chance to score again, either in overtime or an extended period. The game ends as soon as one competitor is ahead of the others, thus winning the game. Sudden death happens exactly like it sounds — brutally and abruptly. For Magnum, this case is like that — he either is going to win big by saving Hani from jail and keeping his friendship with T.C. intact. Or he’s going to lose everything — Hani’s freedom, Makoa’s family, and most of all, T.C.’s friendship.

While Magnum is not one to turn down helping a friend, he does know what happens when he investigates a murder — sometimes the guilty one is right in front of you. The case against Hani seems pretty simple to Det. Katsumoto (Tim Kang). Dr. Ellis Mason was found shot to death in a parking garage by a couple of tourists, who also saw a Saturn fleeing the scene. When HPD pulls over Hani, he is nervous and they bring him in for questioning. They test him for gunshot residue and find blood on his shoes. His story is suspicious as he tells the cops he was a patient of Mason’s, but they cannot find Hani on Mason’s patient roster. While they don’t have a smoking gun, they have enough to charge him.

BROTHERS IN ARMS

Magnum trusts T.C.’s gut, but warns him that unlike T.C.’s father who was accused of a crime he did not commit — Hani might be guilty. When T.C. admits his father actually was guilty of robbing a bank, and he had to live with his grandmother while his father went to prison, Magnum understands why T.C. is so committed to trying to help clear Hani’s name. He wants to keep Makoa from losing his father like he did.

Yet as they find more evidence that supports Hani’s guilt rather than his innocence, Magnum and T.C. grow further apart. And when Magnum turns over evidence to HPD that proves Hani had a motive — T.C. tells him their friendship is over. He thought Magnum had his back and he feels betrayed.

Magnum understands why T.C. is so hurt, but when he gets evidence from medical examiner Dr. Noelani Cunha (Kimee Balmilero from “Hawaii Five-0”), he realizes that perhaps he was wrong about Hani. The evidence suggests it was a woman who shot Mason, and Magnum think that his wife, who thought the good doctor was having an affair, might be the shooter.

Magnum repairs his friendship with T.C., with a little prodding from the-voice-of-reason-Rick, and gathers evidence to convince Katsumoto to bring in Brooke Mason. While the wrapup of the case was a bit anticlimactic, it was a salve for the break in Magnum and T.C.’s friendship. The two make up over Hani and Makoa being reunited and Magnum’s promise to T.C. that they are always good.

CHARMING GUESTS

When the news broke this week that CBS ordered a full-season pickup of the series, many were happy that “Magnum” had been given a chance to continue, despite slipping ratings and Magnum missing a mustache. The show seems to be trying to regain its momentum by booking strong guest stars and focusing its storylines on the series regulars rather than on Magnum’s cases.

Monday’s episode featured two special guest stars — singer-songwriter Cyndi Lauper, who starred as Vanessa Nero, a smooth-talking lawyer, and Elizabeth Rohm, who played Brooke Mason, the wife of the murder victim. Both Lauper and Rohm have ties to “Hawaii Five-0,” as Lauper was the musical guest at this year’s “Sunset on the Beach” season premiere and Rohm played serial killer Dr. Madison Gray in season seven.

Both characters added something different to the episode. Lauper was at her comedic best with a touch of a Queens, N.Y., accent rounding out her “Aloha, honey,” and calling Magnum “Mr. Magnuson” to get him into see Hani — for a fee, of course. Lauper would make a perfect recurring character as I’m sure there are a few “dolls” in Magnum’s world who might have to use her services at some point.

Surprisingly, Rohm played a killer with a bit of heart. When Magnum finally puts the case together and figures out it was the victim’s wife who killed him, he gets her to confess she didn’t mean to shoot him — yet her weepy admission seems heartfelt. Rohm often plays cold-hearted women who are out for just lust and money, but this time around Rohm’s character seems heartbroken by the circumstances. When she thought her husband was cheating on her, killing him seemed justified. But when she finds out her husband was just making money to support her — well, that brought out the remorse and the tears. Luckily, it saved Hani from going to jail for murder.

THE WHITE KNIGHT

While Magnum and T.C. try to clear Hani’s name, Magnum gets a reluctant Higgins (Perdita Weeks) to watch Makoa. With the expert Aunty Kumu (Amy Hill) to back her up with grilled cheese sandwiches and to run defense when social services show up to take Makoa to foster care, Higgins teaches Makoa how to play chess while they wait to hear the fate of his father.

Higgins takes a moment to explain the chess pieces to Makoa while he worries about his father. She focuses on the white knight and speaks about it as if she were also speaking about Magnum. “Players often underestimate it, because it’s unassuming. Its moves seem almost erratic, unpredictable. But quite often, it will surprise you.

“You could almost argue it’s the most important piece in chess. … The knight won’t let you down.”

The metaphor of the white knight comes from the pilot episode, when the fictional Magnum is called the white knight in one of Robin Masters’ books.

It does seem like Magnum is much like the chess piece — unpredictable, but always someone we can count on.

Wendie Burbridge writes the “Five-0 Redux” and “Magnum Reloaded” blogs for staradvertiser.com. Follow her on Twitter and Instagram.