What happens in The Most Terrible Thing?
Spoilers for this episode and earlier events.
Alfred must confront an irreversible action performed in the name of preserving his reign, rather than a conspiracy he can still prevent. Ivar uses a relationship as leverage over Hvitserk, turning diplomacy into another exercise of control within the family. The violence in Iceland destroys Floki’s hope that the settlement can stand apart from revenge.
- Season & episode
- Season 5, episode 17 of 20
- Series order
- 66 of 89
Story connections: Ivar the Boneless, Hvitserk, Floki and Ubbe.
Identify a face in this episode.
Episode references: HISTORY season guide.

Key events and consequences
Judith presents Alfred with an irreversible act he did not authorize, limiting what royal forgiveness could accomplish. Ivar makes Hvitserk's personal attachment into political leverage. Kjetill's violence in Iceland then demonstrates how completely the settlement has reproduced the revenge it was supposed to leave behind.
- Alfred must confront an irreversible action performed in the name of preserving his reign, rather than a conspiracy he can still prevent.
- Ivar uses a relationship as leverage over Hvitserk, turning diplomacy into another exercise of control within the family.
- The violence in Iceland destroys Floki’s hope that the settlement can stand apart from revenge.
Key characters

Ivar the Boneless
Ivar uses a relationship as leverage over Hvitserk, turning diplomacy into another exercise of control within the family.
Character story
Hvitserk
Ivar uses a relationship as leverage over Hvitserk, turning diplomacy into another exercise of control within the family.
Character story
Floki
The violence in Iceland destroys Floki’s hope that the settlement can stand apart from revenge.
Character story
Ubbe
Character story
Judith
Character story
Alfred
Alfred must confront an irreversible action performed in the name of preserving his reign, rather than a conspiracy he can still prevent.
Character story
Aethelred
Character story
Aud
Character story
Eyvind
Character story
Thora
Character storyLocations and story geography
Wessex
Alfred must absorb the consequences of a killing committed to secure his reign while preparing for another threat.
Iceland
The killing of Eyvind's family turns a failed reconciliation into the collapse of Floki's communal hope.
Kattegat
Thora's threatened safety gives Ivar control over Hvitserk even when he sends him away.
These are places in the story. For the real landscapes used on screen, explore the filming-location guide.
The episode breakdown
The title resists being assigned to only one act. Violence is justified as protection in Wessex, enforced obedience in Kattegat and vengeance in Iceland. Those explanations do not make the resulting losses equivalent, but comparing them exposes the danger of treating a desired future as permission for any means. Floki’s position is especially painful because the community was supposed to escape this pattern. Watch how each storyline separates the person claiming necessity from the people forced to live with its consequences.
Themes to follow
- Violence justified as necessary protection or vengeance
- Ideal communities cannot escape responsibility through good intentions