Prime Video Brings Back The Expanse's First Major Villain In A Very Similar Role

Published Sep 12, 2026, 5:00 PM EDT Faith Roswell is a Senior Writer on Screen Rant's Classic TV team. Since earning her degree in Creative Writing over a decade ago, Faith has written articles on film and TV from a variety of different angles. Faith now combines her knowledge of psychology with her love of monster movies to give more insight into what makes the best ones. You may have read her Screen Rant lists and features covering horror, sci-fi, and fantasy, or read her Amazon Top 10 book, "Movie Monsters of the Deep." Faith has had an extensive career as a writer, appearing on BBC live radio, researching true crime for Rotten Mango podcast, and writing for publications including Mental Floss, Atlas Obscura, and The Daily Jaws before beginning here at Screen Rant. This article contains spoilers for season 4 of Reacher.There are some particular kinds of villain that are so versatile, they work in any TV show genre, and Reacher season 4 just proved it by bringing back one of the most iconic sci-fi TV villains of all time. Reacher's latest season has attracted rave reviews for its departure from the previous three season's tropes, and while it has not taken Prime Video's flagship action series into the sci-fi genre, the scientific twist has added both intrigue and horror to the show. Now that a pivotal villain has been unmasked and dispatched, the scene is set for an explosive finale. While Reacher has made some unusual mistakes this season, with the villainous Lila Hoth both seducing and taking advantage of him to get closer to her goal, he was back on form when it came to tracking down and dealing with another villain. Most of Reacher season 4's characters were established early, but the chemist Leo Ahlquist was a mysterious figure who appeared in the photograph central to the events. Cold, mercenary, and perfectly willing to have Reacher killed in order to protect himself, Ahlquist left many viewers with a sense of deja-vu, especially among sci-fi fans. Shawn Doyle's Reacher Villain Is Surprisingly Close To His Character In The Expanse Leo Ahlquist is played by Shawn Doyle, who many may recognize as the politically monstrous Sadavir Errinwright from The Expanse. Errinwright is formidably intelligent, with a deep understanding of how the political landscape works, and a talent for turning fraught situations and tragedies to his advantage. Many of The Expanse's best episodes show the ways in which politics can become a weapon, with Errinwright's actions central to many of the most disturbing plots in the show. Reacher's Ahlquist resembles a version of Errinwright with science as a specialty instead of politics, even down to the study of a bioweapon. Errinwright operated in the shadows while projecting a calm and competent demeanor, which led to his knowledge being valued while his ambitions were underestimated. The same can be said for Ahlquist, whose scientific work in pesticide development was considered essential, but his success was due to additional work developing chemical weapons and allying with a genocidal leader. The differences between the two characters are few, yet they play very different roles in their respective shows, proving that an excellent villain archetype can transcend genres, especially when played by an actor who excels at portraying formidably intelligent antagonists. Shawn Doyle Also Played A Similar Role In Star Trek: Discovery Shawn Doyle is a versatile actor, but has become associated with playing corrupt masterminds who are often brought down by their own arrogance. The Expanse and Reacher are not the only shows to feature Doyle in this role, with Star Trek: Discovery borrowing a character trick from The Expanse through Ruon Tarka. Like Ahlquist, Tarka is a scientist, and like both Ahlquist and Errinwright, Tarka is involved in background corruption. All three use different "masks," with Errinwright's demeanor hiding his true nature, Ahlquist using scientific progression as a shield, and Tarka's arrogance stopping people from looking too closely. That said, Doyle plays all three characters slightly differently despite their underlying philosophy that the ends justify the means. Errinwright projects power through being self-contained and outwardly reasonable, and when Reacher first meets Ahlquist, he appears very similar. However, this demeanor is brittle, and without his men to act on his behalf, Ahlquist is quickly reduced to a desperate coward whose only goal is self-preservation. Tarka is more complex still, motivated by grief rather than self-enrichment and becoming the most tragic villain in Star Trek. Reacher might be a reassuringly predictable action thriller with very little in common with The Expanse or Star Trek at first glance, but all three shows feature corruption on an unfathomably massive scale, and characters willing to risk everything to stop it. This is where villains like the characters played by Doyle work so well. On a small scale, villains can be violent and obvious, but the higher the level of corruption, the more detached the antagonist can become. While Ahlquist is dead, it is likely that Reacher will meet someone similar again as this character type is timeless. Release Date February 3, 2022 Network Prime Video Showrunner Nick Santora Cast Maria Sten Frances Neagley Without a phone and traveling light, former military police officer Jack Reacher drifts between American towns, embroiling himself in local crimes and bringing justice in his wake. Based on the series of novels by Lee Child, Reacher's journey offers him an intimate understanding of the nation he once served.