Slow Horses Second Desk, Explained

In "Slow Horses," second desk is a codename for the Deputy Director-General of MI5. But what does it actually mean, what does second desk do, and who currently has that title in the show? 

With its unmatched wit, outstanding performances, and top-notch spycraft, "Slow Horses" is easily the best spy show on TV. But there are a few frustrating things about the Apple TV series. For instance, season 5 of "Slow Horses" made a tonal shift towards comedy that was jarring following the deeply tragic events of the previous season. Then there's Kristin Scott Thomas' Diana Taverner, who from the outset seemed destined to take control of MI5, but was continually thwarted in that regard by one of the most weaselly characters on TV today. 

James Callis' Claude Whelan filled the role of Director-General of the British Security Service in "Slow Horses" since the beginning of season 4, when he took over from the disgraced Dame Ingrid Tearney (Sophie Okonedo). After Whelan's arrival, Taverner, who'd been acting as interim Director-General, was forced to return to her Deputy Director-General role despite being far more qualified for the top job than the new head of the service. Things didn't change until the end of season 5, with Taverner remaining second desk to Whelan's first desk throughout before a shock ending upended the hierarchy and led to Taverner taking the top job. 

But since Taverner essentially did Whelan's job for him ever since he arrived at MI5 headquarters, what does "second desk" actually involve, and is it a term used in the real-life Security Service? Read on for everything you need to know about "Slow Horses" second desk.

Just as the real MI5 has a Director-General and a Deputy Director-General (there are also several assistant Directors General), the Security Service of "Slow Horses" is headed by a Director-General and a Deputy who reports to the former. That means Diana Taverner was essentially second-in-command for the first five seasons of the show, first reporting to Dame Ingrid Tearney and then to Claude Whelan — a fact that continued to irk the ever-ambitious and shrewd senior civil servant.

In the original "Slough House" novels, written by Mick Herron, the top two positions at MI5 are referred to as first and second desk, and the Apple TV series maintains this slang. However, it's not clear that the real-life MI5 Director-General and Deputy are actually referred to using the same nicknames. According to the official MI5 website, the Director-General is known as "DG" within the service, but "Slow Horses" does such a convincing job of depicting its version of MI5 that you can easily believe that first and second desk are real-world terms.

So, what does the second desk in "Slow Horses" actually do? Well, as we've seen throughout multiple seasons, Taverner serves as both the Deputy Director-General of MI5 and the head of operations, which is why Kristin Scott Thomas' character has overseen multiple missions from the control room at Regent's Park headquarters, aka "The Park." Both first and second desk work from this building, which is slightly different from the real MI5 headquarters, located at Thames House in Westminster. Otherwise, second desk shares a lot of the responsibilities of first desk, mainly in terms of liaising with politicians to keep them updated on developments within the service.

Throughout the first five seasons of "Slow Horses," Diana Taverner has proven there's a lot more to being second desk than backing up the Director-General and overseeing operations. The character has consistently worked behind the scenes to manipulate her career prospects, leaking documents and authorizing covert operations designed to make it easier for her to usurp her superior. Many of those attempts failed, but now things have changed.

In "Slow Horses" season 5, the show's most spineless character finally stood up for himself. Claude Whelan was backed into a corner after a politician threatened to reveal his illicit meetups with a sex worker, and for a while it seemed as though Taverner would finally get a clear shot at first desk. Then, Whelan used the intelligence at his disposal as head of MI5 to threaten his blackmailers and retained his job at the top, seemingly cementing his position. However, Jackson Lamb ultimately managed to blackmail Whelan into resigning, which means Taverner will be first desk in season 6.

It remains unclear who will take on the role of second desk, but with Taverner now heading MI5, she'll surely have to deal with more of the surreptitious power brokering in which she engaged previously. Whoever takes on second desk moving forward better prepare themselves — and watch their back, too.