Never let it be said that Ragnar Lothbrok was a man without a sense of vision, but it takes the steady hand of eldest son Bjorn Ironside to take the assembled great army onward toward its destiny. Likewise, tonight’s installment of Vikings takes the slow, deliberate approach before building to a devastating crescendo as the heathen army finally makes its move to avenge the death of its slain king. But it is Michael Hirst’s decision to leave the battle to the imagination of the viewer that generates the breathtaking power of “Revenge.” The effectiveness of showing viewers only the subtle detailed nuances leading up to the departure of the largest Viking army ever assembled cannot be overstated as it prepares to confront the Saxons on the first leg of its revenge tour. It’s easy to forget that Vikings relies as much on introspection as it does on elaborate battle sequences to bring its characters and stories to life. And one of the first situations that must be addressed is one of leadership since Ivar feels his father meant for him to lead the army into battle. There’s a certain unpredictability in Bjorn Ironside that plays more as a strength than a weakness, so when he informs his brothers in no uncertain terms that he will lead the army, the forcefulness of his resolve rings true even though Ivar clearly feels slighted. In fact, not only does he refuse to share power with his brother, the other assembled kings from Sweden and Denmark must take their marching orders from Ragnar’s eldest as well. Speaking of unrequited love, Ubbe’s marriage to Margrethe brings with it a number of twists and turns and addresses a lifestyle hinted at back in season one with Ragnar, Lagertha, and Athelstan. However, Ubbe’s decision to share his wife with his brother Hvitserk seems fraught with conflict down the road, though on the eve of war, much could happen to alter that dynamic. Does the “Bridal Race” mirror the obstacle course such a relationship will invariably evolve into? Nothing of importance in Norse culture is accomplished without cultic sacrifice, and because of the enormity of the endeavor, Queen Lagertha chooses to take it up a notch. It’s not clear whether Earl Jorgensen volunteered or his brother made the decision for him, but either way, the young man seems honored to have Lagertha drive a blade into his chest. While this human sacrifice takes place, Bjorn and Astrid remove themselves from the ceremony and enjoy yet another sexual encounter. Is Bjorn’s thrusting set against his mother’s blade a bit too obvious? Yes, but it sets up nicely Lagertha’s revelation that she’s quite aware that her sexual partner is also sleeping with her son. That she doesn’t appear bothered by it only adds to the potential drama, and when she tells Astrid. “I hope it was worth it,” her young protege best sleep with one eye open. Another strength of “Revenge” can be found in the exchange between King Ecbert and his son Aethelwulf, whose concern that his father “no longer acts like a king” is clearly reason to be concerned as they await the return of Ragnar’s sons. And in another poignant scene in which the character’s plight would ordinarily engender empathy, we can only stand by as voyeurs while Aethelwulf asks his father if he even loves his son. That Ecbert can’t or won’t respond only adds to the mystery of the man who took his own son’s wife as his mistress. And while we feel for Aethelwulf’s squabbles with his father and Ecbert mourning the death of his friend, it’s King Aelle’s naivete and hubris that quickly remind us why we hate him so much and help us understand how Judith turned out as she did. Though we intellectually understand that this is the greatest Viking army ever assembled descending on the Saxons, its sheer scope doesn’t reveal itself until the end of the episode as it rises over the final hill.