04/17/2026
James MacArthur heard it first on a Honolulu set—a director shouting, "Book 'em, Danno!"
He didn't know it yet, but that line would follow him for the rest of his life.
For eleven seasons on Hawaii Five-O, MacArthur played Detective Danny "Danno" Williams—the calm, loyal partner to Jack Lord's stoic Steve McGarrett.
The phrase became a national catchline, echoing from living rooms to late-night monologues.
But behind the island sunsets and surfside car chases, the reality was more complicated than it looked on screen.
The show premiered in 1968 and ran for 12 seasons, becoming the longest-running police drama in American television history at the time.
MacArthur joined after the pilot. The original actor cast as Danny Williams, Tim O'Kelly, didn't test well with audiences—they thought he looked too young.
Producer Leonard Freeman remembered MacArthur from a small role in the Clint Eastwood film Hang 'Em High and offered him the part.
For over a decade, MacArthur became the dependable second-in-command. The one who defused bombs, went undercover, and balanced out McGarrett's mythic intensity with human relatability.
And at the end of many episodes, McGarrett would deliver the line: "Book 'em, Danno!"
According to MacArthur, the nickname itself came from Jack Lord. "Jack and I were shooting a thing one day and we both had our guns out and were going to surround someone. Jack said something like, 'Go down there, Danno,' and I just stopped and said, 'Danno? Who's Danno?' We cut and Jack said, 'You know, I had a friend named Dan when I was a kid, and we used to call him Danno.'"
And just like that, television history was made.
But the partnership between MacArthur and Lord wasn't always smooth.
There were rumors. Tensions. Different accounts of what happened behind the scenes.
William Smith, who replaced MacArthur in the final season, claimed that MacArthur left "because Jack Lord wouldn't let him have a dressing room. He had to change in the prop truck for eleven years."
MacArthur himself told a different story.
In 1979, after eleven seasons, he was on vacation in South America when he made a decision.
He called his agent from Cuzco, Peru.
"Tell CBS I'm not coming back," he said. "If they want to talk to me, I'm on the Amazon River."
This was before cell phones. Before instant communication. He literally called from a remote location and quit.
Then he got on a little riverboat, slung a hammock, and started down the Amazon for two months.
"It was just time," he explained years later. "The show was running downhill badly. I didn't make any fuss. People thought I wanted to make more money or something. In fact, what I did was I went to the headwaters of the Amazon."
He elaborated in another interview: "I grew bored. The stories became more bland and predictable, and presented less and less challenge to me as an actor."
No scandal. No dramatic exit. Just a quiet decision that he'd done everything he could with the role.
Fans were stunned. The network had no explanation ready.
In the 12th and final season, Hawaii Five-O simply went on as if Danny Williams had never existed. McGarrett never mentioned his name. No farewell episode. No explanation.
The show was cancelled one year after MacArthur left.
What most people forget is who James MacArthur was before Hawaii Five-O made him famous.
He was Hollywood royalty. The adopted son of legendary actress Helen Hayes—known as the "First Lady of the American Theatre"—and playwright Charles MacArthur.
His godmother was silent film star Lillian Gish.
He'd been Disney's golden boy in the late 1950s and early 1960s, starring in Swiss Family Robinson, Third Man on the Mountain, and Kidnapped.
He'd made his Broadway debut in 1960 opposite Jane Fonda in Invitation to a March, winning a Theatre World Award.
He'd left Harvard in his sophomore year to pursue acting full-time.
And then Hawaii Five-O made him famous in a completely different way—as the dependable sidekick in paradise.
After leaving the show, MacArthur didn't chase fame's second wave.
He guest-starred on shows like Murder, She Wrote, Fantasy Island, and The Love Boat. He returned to theater. He directed a production of his father's play The Front Page at the Honolulu Community Theatre.
He invested his Hawaii Five-O earnings in Hawaiian real estate and became wealthy.
He appeared at conventions where fans still shouted "Book 'em, Danno!" across rooms.
And he always laughed and tipped his hat.
"Funny," he once said. "It started as a line. Ended as my echo."
In 1997, MacArthur returned to Hawaii Five-O for an unaired reboot pilot—playing Danny Williams, who had become Hawaii's governor. Jack Lord, in declining health, didn't participate.
When the 2010 CBS reboot of Hawaii Five-0 (with a zero instead of an O) launched, there were negotiations for MacArthur to make a cameo appearance.
He died before it could happen—on October 28, 2010, at age 72, of natural causes in Florida.
The November 1, 2010 episode of the new series opened with a tribute to him.
James MacArthur spent 11 years being the perfect second banana. The reliable partner. The guy who made Jack Lord's McGarrett look good.
And when he'd had enough, he didn't make a fuss or demand more money or fight for top billing.
He called from the Amazon River and said he wasn't coming back.
Then he lived the rest of his life on his own terms—not as Danno, but as himself.
The line followed him forever. "Book 'em, Danno!" became as much a part of American pop culture as "Beam me up, Scotty."
But James MacArthur proved something important: you can walk away from the thing that made you famous and still have a life worth living.
Even if that life includes people shouting your character's nickname at you in airports for the next 30 years.
