The episode is notable for its significant stylistic departure from the rest of the series, as it follows protagonist Kevin Garvey through an ethereal, afterlife-like realm as he works to purge the ghost of deceased Guilty Remnant leader Patti Levin from his mind.
"International Assassin" received wide acclaim from critics, who praised the episode's surreal presentation and thematic depth, as well as Justin Theroux's lead performance.
Virgil informs Kevin that he has already made a generous donation to Patti's campaign that grants him a personal meet-and-greet, during which he will collect a gun from the bathroom to assassinate her.
In the car, Patti reads from the brochure for Jarden tourists given to them by Virgil, which says that the well was constructed by area's indigenous tribes as an axis mundi between the realms of the living and the dead.
Patti's death triggers a violent earthquake; Kevin begins climbing out of the well, but emerges in Virgil's yard back in the real world.
Cuse noted that many of the episode's plot details started as jokes in the writers' room, such as Patti being a senator with the Guilty Remnant as a political party.
[2] Series star Justin Theroux confirmed that Kevin was dead during the events of "International Assassin," per the script for the preceding episode, "A Most Powerful Adversary".
Lindelof took inspiration from Die Hard, whose score consists largely of Beethoven compositions, in choosing the piece as an operatic flourish for the episode.
"International Assassin" marks the first of multiple trips Kevin makes to the afterlife in the series, including a second visit to the hotel in the season 2 finale, "I Live Here Now."
[5] "International Assassin" received widespread critical acclaim, with particular praise given to the episode's surreal setting, Lindelof and Cuse's script, and the performances of Theroux and Ann Dowd.
"[6] Jen Chaney of The New York Times called the episode a "brain-shredding masterpiece," finding numerous parallels to 1970s films such as All the President's Men and A Clockwork Orange.
[8] Alan Sepinwall of Uproxx also compared "International Assassin" to The Sopranos, acknowledging its potential to polarize viewers with its surreal storytelling and stylistic departures from the rest of the series.
Sepinwall felt the episode affirmed the series' "unflinching commitment to its themes about grief, spirituality, and madness" and praised how it handled its unexpected premise.
[9] Libby Hill of the Los Angeles Times felt the episode's strength rested on Theroux's performance, which she named one of the finest on television.
[12] Damon Lindelof and Nick Cuse were nominated for the Writers Guild of America Award for Television: Episodic Drama for writing "International Assassin".