“Reacher” returns for its fourth season on Prime Video today, with the first three episodes streaming together before the show shifts to weekly releases. The eight-episode season concludes September 16.

Alan Ritchson is back as Jack Reacher, the wandering former military police investigator at the center of Lee Child’s novels. Season 4 adapts “Gone Tomorrow,” the thirteenth book in the series. The action moves to Philadelphia after a tense subway encounter pulls Reacher into a government conspiracy.

The Philadelphia setting is a shift for the show. The first three seasons were built around small towns, using that scale to isolate Reacher against local corruption and violence. Season 4 trades that format for a bigger city and a wider conspiracy plot, based on the marketing materials Amazon has released ahead of launch.

Christopher Rodriguez-Marquette steps into the role of Jacob Merrick this season, replacing Jay Baruchel. Cast details were confirmed by Forbes and Men’s Journal ahead of the premiere.

Amazon is also using the finale date to launch a companion series. “Neagley,” starring Maria Sten as Reacher’s former army unit colleague Frances Neagley, premieres September 16 alongside the Season 4 finale. It expands the “Reacher” universe into a second show for the first time.

Season 5 is already confirmed and in production, based on the novel “Make Me,” with a target release window in 2027. The renewal came before Season 4 had even premiered, reflecting Amazon’s confidence in the franchise following strong viewership for the first three seasons.

Ritchson has said in past interviews that he trained extensively to match the physical presence Lee Child describes in the books. The show has leaned on that scale as a selling point across its marketing since the first season debuted in 2022.

Reacher has been one of Prime Video’s steadier performers since that debut, consistently ranking among the platform’s most-watched titles during its release windows. The show remains a centerpiece of Amazon’s push into event drama, alongside other recent additions to Prime Video’s original lineup.