What's on TV this week—Slow Horses and The Traitors are back

Welcome to What’s On, our weekly roundup of notable shows. Here is what’s happening on TV from Sunday, September 13 to Saturday, September 19. All times are Eastern.

Neagley (Prime Video, Wednesday, series premiere) As Reacher season four comes to an end, the Jack Reacher universe will continue on with this new spinoff series, focused on Frances Neagley, (Maria Sten) a Chicago-based private investigator and former military protege of Lee Childs’ hulking vigilante. (Speaking of, Alan Ritchson appears in a guest-starring role). When Neagley learns that a beloved friend from her past has been killed in a suspicious accident, she seeks answers and justice, a mission that will pull her into a dangerous web of cult compounds and psychological control. Greyston Holt, Jasper Jones, Adeline Rudolph, Matthew Del Negro, and Damon Herriman round out the cast. Look out for The A.V. Club’s review on Tuesday. 

Slow Horses (Apple TV, Wednesday, season six premiere) Adapting not only one but two Mick Herron’s novels (Joe Country and Slough House), the sixth season of this Gary Oldman-led spy thriller will fittingly pack a lot of secret-agent action into a mere six episodes. Jackson Lamb (Oldman) and his team of misfit MI5 agents are on the run from mystery assassins all while trying to survive the “fatally high-stakes game of retaliation and revenge” set forth by Diana Taverner (Kristin Scott Thomas). Returning cast members include Jack Lowden as River Cartwright, Hugo Weaving as Frank Harkness, and, notably, Olivia Cooke as Sidonie “Sid” Baker, who we haven’t seen since season one. The A.V. Club’s premiere recap drops on Wednesday. 

The Traitors: New Blood (NBC, Thursday, 8 p.m., series premiere) Host Alan Cumming is back with tartan flamboyance and delicious camp for another installment of TV’s best whodunnit, but his is about the only familiar face you’ll recognize in this spinoff of The Traitors. That’s because this time around, instead of beloved reality stars and C-list celebrities, the cast will be made up of 22 everyday Americans deemed cunning enough to move into Ardross Castle and ruthlessly weed out the dastardly Traitors from the determined Faithfuls. The all-civilian edition will premiere with two back-to-back episodes; tune in for The A.V. Club’s premiere recap on Thursday night.