Spoilers for this episode.
The Franks deliver the treasure agreed to end the siege, but Ragnar's illness keeps the Vikings outside Paris. Bjorn helps arrange what appears to be his father's final wish: a Christian funeral inside the city. Lagertha, Rollo and Floki speak over Ragnar's closed coffin, believing that he is dead. Their private farewells expose affection, resentment and the anger Floki still feels toward Athelstan, while Bjorn keeps the plan hidden.
The coffin is carried through the gates and into the cathedral. During the service Ragnar suddenly rises, kills the bishop and takes Gisla hostage. He forces a path back toward the entrance and makes the guards open the gates for his waiting warriors. Bjorn receives his weakened father as the Vikings enter and plunder Paris. The funeral has allowed them to pass the defences that defeated two direct attacks, though Ragnar's companions resent being excluded from the deception.
Most of the fleet prepares to return to Kattegat, with Rollo volunteering to stay behind with a smaller force. Charles offers him land, a title and marriage to Gisla if he will defend Paris against future Viking attacks. Gisla angrily rejects the proposed match when Rollo comes before her, and he answers with a greeting in her language. On the homeward voyage, Ragnar turns to Floki and tells him that he knows Floki killed Athelstan.