Five History Hit episodes are bundled together here, each tracing a different order of soldiers built around killing, infiltration, or terror. The film opens with the Hashashin, the medieval Ismaili sect whose name gave English the word assassin, then moves to the Berserkers, the Norse warriors said to fight in trance-like rage. From there it covers the Varangian Guard, the Norse mercenaries who became the Byzantine emperor's personal bodyguard, the Aztec Eagle Warriors who captured enemies for ritual sacrifice rather than killing them outright, and finally the Ninja, Japan's clandestine agents of espionage and assassination. Each segment uses expert interviews, historical maps, and reenactment footage to walk through how these units were recruited, trained, and deployed, and what made them feared in their own time. Presented as a chaptered compilation rather than a single narrative, it works as a survey of how different cultures built and mythologized their elite killers across roughly a thousand years of history.