'Vikings' creator takes us inside this week's vengeful episode

This post contains spoilers for Vikings Season 4, episode 17, titled "The Great Army."

In the aftermath of Ragnar's death, everyone is out for revenge on Vikings -- especially his sons, Bjorn, Ivar, Ubbe, Sigurd and Hvisterk, who are ready to wage war against Saxon kings Aelle and Ecbert for killing their famous father. (Just to add to the vengeance-fest, Ivar and Ubbe are also out for Lagertha's blood, after she murdered their mother, Aslaug, and installed herself as ruler of Kattegat.)

Ragnar's death will clearly have far-reaching implications for everyone on Vikings, from his sons and ex-wife to his former friend Floki and enemy-turned-ally Ecbert.

Ecbert certainly seems to have been changed by his role in Ragnar's death, as evidenced by his multilayered scene with Alfred in episode 417, in which he instructs Athelstan's son in the art of ruling.

Vikings creator and writer Michael Hirst has given Mashable an inside look at the scene with annotated script pages, sharing Ecbert's motivations and how the scene was enhanced by Linus Roache's performance.

Vikings airs Wednesdays at 9 p.m. on History.