What Is Loki?

Loki is a Disney+ MCU series that began in 2021 and concluded with its second season in 2023. Starring Tom Hiddleston in the title role, the series follows a variant of Loki — the one who escaped with the Tesseract during the events of Avengers: Endgame's time heist — as he's captured by the Time Variance Authority (TVA) and thrust into a world-altering conspiracy involving the nature of time itself.

Of all the MCU Disney+ series, Loki has had the most direct and far-reaching impact on the broader MCU narrative, directly introducing the multiverse concept that now underpins the entire Multiverse Saga.

Season 1: The TVA and He Who Remains

Loki is brought to the TVA — a bureaucratic organization that monitors and "prunes" timeline deviations — where he meets Agent Mobius (Owen Wilson) and begins uncovering a much larger conspiracy. The season's central mystery revolves around a "Variant" Loki (Sylvie) who has been attacking the TVA from within.

The season finale introduced He Who Remains, a variant of Kang the Conqueror played by Jonathan Majors. His death at Sylvie's hands is the inciting event that fractures the Sacred Timeline and unleashes the multiverse — setting the stage for Spider-Man: No Way Home, Doctor Strange in the Multiverse of Madness, and beyond.

Season 2: Loki Becomes Something Greater

Season 2 expanded the scope dramatically, introducing "time-slipping" — Loki involuntarily jumping through time — and a crisis threatening the destruction of the TVA's Temporal Loom. The season brought in new characters including Ouroboros (Ke Huy Quan) and explored the human lives of TVA agents who were taken from their timelines.

The finale is among the most emotionally resonant in MCU TV history. Loki — a character whose entire arc began with a desperate hunger for a throne — willingly accepts an eternity of isolation to hold all timelines together. He becomes the God of Stories, the keeper of the multiverse's branches.

Why Loki Matters to the Wider MCU

  • Introduced the multiverse: The events of Season 1 directly caused the multiverse to branch, enabling all subsequent multiverse storylines.
  • Established Kang as the primary antagonist: He Who Remains and his variants are the central threat of the Multiverse Saga.
  • Completed Loki's redemption arc: His journey from villain in Thor (2011) to selfless guardian of all existence is one of the MCU's longest and most satisfying character arcs.
  • Changed the TVA's role: The reformed TVA remains a presence with implications for future stories.

Tom Hiddleston's Performance

Tom Hiddleston has played Loki across the MCU since 2011 and delivered some of his finest work in this series. The quieter, more introspective demands of television allowed him to portray vulnerabilities and growth that the theatrical films rarely had space for. His work in the Season 2 finale in particular drew widespread critical praise.

Key Characters

CharacterActorRole
LokiTom HiddlestonAsgardian variant; eventual God of Stories
SylvieSophia Di MartinoFemale Loki variant; killed He Who Remains
Mobius M. MobiusOwen WilsonTVA agent; Loki's unlikely ally
He Who Remains / KangJonathan MajorsMultiversal villain; Season 1 finale antagonist
Ouroboros (OB)Ke Huy QuanTVA technician; Season 2 key figure

Should You Watch Loki?

Absolutely — and it's essential viewing before engaging with Phase 5 and beyond. Even for viewers who primarily watch MCU films, Loki provides critical context for why the multiverse is broken, who the villains are, and what happened to one of Marvel's most beloved characters. It's also simply excellent television in its own right.