One of the biggest showstoppers, at the end of the first half of “Vikings” Season 4, was the decade-long disappearance of King Ragnar (Travis Fimmel) — and his reemergence in Kattegat after his sons had grown.

For “Vikings” creator and writer Michael Hirst, those boys were a powerful motivator for Ragnar to return after deserting his people.

“He loves his children — his boys — and he wants to know what happened to them, and how they’ve grown up,” he explains. Of course, that’s only part of Ragnar’s story.

“Possibly the more overwhelming reason is he has unfinished business in Wessex, which has drawn him down from the mountain,” Hirst continues. Given the betrayal by King Ecbert (Linus Roache) and the idea that he has another son in Wessex, you can’t really blame Ragnar for wanting to return there to settle his beef.

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Why abandon his people in the first place, though?

“Ragnar chose to disappear because he’d been defeated. In Viking society, which is essentially a meritocracy, a defeated leader or king would normally he killed and replaced by the toughest guy on the block,” Hirst says. “But in Ragnar’s case it was different because he was too famous just to forget.”

As for what he did in his time away, Hirst doesn’t really know and that’s how he prefers it. “I don’t know where he went. I don’t know what he did when he went missing,” he explains. “I suspect he lived a fairly solitary life and he must have often contemplated… Not suicide. That would be a big thing for a Viking, like it would be for a Catholic. A Catholic commits suicide and you can’t get into heaven. Vikings can’t do it because they can’t get to Valhalla because they haven’t died well.”

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Those times are over now. Ragnar is back and has a mission: “Vikings believe in fate and I think he thinks fate still has something in store for him,” Hirst teases.

As for what that fate could mean, for Ragnar or his people, remains a mystery. At the very least, his return is good news for Ivar the Boneless (Alex Andersen), who shares many traits with his father — and has a lot to learn from the Viking king.

“Vikings” airs Wednesdays at 9 p.m. ET/PT on History Channel.

Posted by:Chris E. Hayner

Chris E. Hayner is equal parts nerd, crazy person and coffee. He watches too much TV, knows more about pro wrestling than you do and remembers every single show from the TGIF lineup. You may have seen him as a pro-shark protester in "Sharknado 3." His eventual memoir will be called "You're Wrong, Here's Why..." TV words to live by: "I'm a firm believer that sometimes it's right to do the wrong thing."