Apple TV today announced the release date for the sixth season of its popular spy drama series Slow Horses , based on the books by Mick Herron . The show stars Gary Oldman as the leader of a ‘dumping ground’ division inside MI5 known for its blunders more than its successes. Season 6 will premiere on September 16, with new episodes dropping weekly through October 21. The first look image featured above shows Oldman in his iconic form as Jackson Lamb. Slow Horses is one of Apple’s bigger hits, and represents a huge success for the service’s British drama team. Officially, the show is already renewed for a seventh season, but an eighth is also believed to be in production at the moment. The show has also been a critical hit, earning the company numerous Emmy and BAFTA TV awards. All five seasons streaming now on Apple TV are certified fresh on Rotten Tomatoes. What will be interesting to see is whether the tone of the darkly comedic show changes going into season six, as there has been some talent changeover.…