When Vikings returns to History on Wednesday, Nov. 28 (9/8c), it'll be a whole new world. Now that Ivar (Alex Høgh) is King of Kattegatt, Lagertha (Katheryn Winnick), Bjorn (Alexander Ludwig), Ubbe (Jordan Patrick Smith) and Heahmund (Jonathan Rhys Meyers) will have to flee Scandinavia for England to hide from his deadly vengeance. But once they arrive in England, where the young King Alfred (Ferdia Walsh-Peelo) now rules, the Vikings will find themselves in the midst of another political upheaval, as Alfred's progressive values clash with the traditionalists around him.

Meanwhile, back in Kattegatt, Ivar and Hvitserk's (Marco Ilsø) already uneasy relationship becomes more perilous as Ivar's ego grows to dangerous new heights, with his crown shielding the maniacal king from any consequences or criticism. And then there's the fact that over in Iceland, Floki (Gustaf Skarsgard) offered to sacrifice himself to the gods in the hopes of saving his community from in-fighting and violence.

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Alliances will be formed, relationships will be tested and, as always, there will be deaths in the episodes to come. Ahead of the midseason premiere, TV Guide spoke with creator Michael Hirst to break down the eight most important things you need to know going into the back half of Season 5.

1. Ivar's reign will usher in a new Dark Age. It should come as no surprise that Ivar's ascension to King of Kattegatt won't transform him into a benevolent ruler. But even as Ivar kickstarts his reign of violence, he will still manage to toe the line this season between ruthless antagonist and empathetic antihero.

"Ivar continues to be a complex character who does terrible things but never quite stops us from, one, being interested in him, and two, actually engaging with him," Hirst says, adding that Ivar's physical disability continues to push Ivar to prove he's not only equal to his brothers but perhaps even better than them — something Ragnar encouraged before he died.

This need for validation will drive Ivar (and his id) this season, as he attempts to secure himself a spot in Valhalla alongside his father as one of the great Viking heroes.

2. Lagertha will reinvent herself. After the devastating midseason finale, Winnick teased that Lagertha would be a changed woman now, and she wasn't exaggerating. "Lagertha actually sort of reinvents herself," Hirst confirms.

"She has an interesting season ahead, a season of great and profound changes," Hirst adds. "A season in which she really comes to question who she is and what she's been doing." Per the creator, this questioning will lead Lagertha to confront some "hard truths," including ones about Rollo and her own ambitions.

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But not everything this season will be dark and difficult for our favorite shieldmaiden. "She also gives herself another chance to fall in love," Hirst says. "You would have thought by this stage that men were pretty much off the menu, but there is someone interesting enough for her to modify that opinion and to potentially fall in love with."

3. Rollo's return comes with a hidden agenda. If you thought Rollo (Clive Standen) must be up to something when you saw him sailing toward Kattegatt, you clearly know the former Viking warrior very well. On the one hand, he's there to take political advantage of the situation, offering Ivar the not-so-optional deal of becoming trading partners and to strike a bargain that would provide Rollo with warriors in future conflicts. However, that's not all Rollo is after.

"Of course, his real reason for going back to Kattegatt is very different and personal and private. And it is to do with unfinished business as he sees it in his relationship with Lagertha," Hirst teases. "So the two things come together, obviously. But I have to say, it was lovely to see Rollo back on the screen and headed back to Kattegatt. As he says himself in the very first episode, 'I kind of miss the place.'"

4. Bjorn won't stop until he gets revenge. After losing Kattegatt to Ivar, Bjorn is dead set on taking back his home and getting revenge on his brother. "He'll go to the ends of the Earth, really," Hirst says.

Growing up in Ragnar's shadow and suffering such a public defeat, Bjorn will be out to prove himself this season as the true heir of Ragnar once and for all. "It's Ivar who says, 'I'm the one who's achieving things, I'm king of Kattegatt, you're a loser," Hirst explains. "And so it behooves Bjorn as the eldest son of Ragnar to [refute] that argument."

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In Bjorn's single-minded quest to do so, he'll find himself butting heads with several of his allies who don't share Bjorn's priorities or methods. But a new, yet familiar face will enter Bjorn's life and help drive him on his violent path forward.

5. Lagertha and Heahmund's relationship will be tested. With Lagertha and her close allies forced to flee Scandinavia for England, Lagertha will find her dynamic with her lover Heahmund radically changed as his loyalties and motivations once again come under question.

"He's back on his home territory now and Lagertha, just like the audience, doesn't really know what to expect when he gets back ... and indeed whether he's entirely been telling the truth and who he is," Hirst says. "I don't know whether it's a spoiler or not, but they do have a deep relationship, which to some extent might surprise her."

Even if Heahmund is telling the truth about his love for Lagertha, he'll still have to reconcile his relationship with a pagan with his devotion to the Church — particularly if he has any intentions to reclaim his former position of power.

6. Hvitserk's journey of self-discovery is just getting started. If you're still wondering why Hvitserk betrayed Ubbe to side with Ivar, join the club. The young Viking will spend much of the back half of Season 5 asking the exact same question.

"The consequences of that decision and the consequences of having to put up with Ivar's tyranny are terrible, and he beats himself up and will actually continue to beat himself up and go to some pretty dark places because of that decision. But he knows deep down that there must have been a reason for him to jump ship," Hirst says. "Did the gods make him jump and if so, what did the gods have in store for him? Was he meant to kill Ivar?"

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This whole questioning is part of Hvitserk's overall quest to discover who he is. While his brothers may feel comfortable in their roles as the sons of Ragnar Lothbrok, Hvitserk continues to find that a heavy burden to bear. But if you're expecting Hvitserk to undergo a major epiphany in these next 10 episodes, you're in for a major disappointment. "He's an evolving character and I'd love to track that evolution ... right down to the point when he does discover, he does realize why he jumped ship. But that's a long way in the future," Hirst teases.

7. Ivar will fall in love. While Ivar may be a ruthless king, he will show his softer side to one person this season. But don't think it's a coincidence that this new woman comes into Ivar's life just as he rises to power. It seems in this new woman that Ivar may meet his match in many ways, but particularly when it comes to skilled manipulation and cruelty.

"Anyone who shows [Ivar] what he thinks is real affection, even perhaps love, he's going to be at their mercy," Hirst explains. "It doesn't mean that he doesn't personally do terrible things, but you can understand the syndrome that he has. So she sets him in motion, in a way, some of the greater cruelties that happen in Kattegatt. And yes, he's vulnerable, he's vulnerable to that [manipulation]. She is an interesting character and of course she manipulates the situation to give him what he seems to want, but it's clearly also to her advantage to do so."

8. Floki's journey in Iceland will come to a harrowing conclusion. When we last saw Floki, he was offering himself up as a sacrifice to the gods to save his fledgling colony in Iceland. And while we can't confirm or deny Floki's fate at this time, Hirst does promise that the payoff of the Icelandic storyline "is extraordinarily powerful."

"You don't see it coming. But when you see it, it makes total sense of why Floki went there, what he's learned and I was very proud of that storyline," Hirst says. "[Floki's experiment in Iceland] is part of the universe of Vikings, of this world I created. It's an essential part because I'm talking all the time about the relationships between men and women and the gods, and this is at the sharp end of that discussion. But what happens in the end in Iceland is so harrowing, so extraordinary that I think it will provoke a lot of thought and conversation."

Vikings premieres Wednesday, Nov. 28 at 9/8c on History.

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