Apple TV has released the official trailer for the sixth season of its spy thriller Slow Horses, teasing the most perilous storyline yet for the misfit MI5 agents of Slough House. The show, led by Gary Oldman as the cantankerous Jackson Lamb, has become Apple TV's longest-running series and continues to draw praise for its rapid, consistent release schedule compared with rival streamers.

Season six draws primarily on the sixth and seventh novels in Mick Herron's Slough House series, Joe Country and Slough House, and sees MI5 now run by new First Desk Diana Taverner (Kristin Scott Thomas), whose actions trigger a wave of retaliation that leaves current and former Slow Horses being killed off one by one. The trailer shows Lamb confronting Taverner in her garden at night, while the surviving team scrambles to protect itself, with River (Jack Lowden) appearing to be the next target as the season heads towards its premiere next month.