Get into Slow Horses on Apple TV+ with this spy slang glossary


"Slow Horses" on Apple TV+ features Gary Oldman as Jackson Lamb, plus a lot of muttered words and phrases you might need help understanding.
Photo: Apple TV+

There’s nothing like discovering a truly rich and deep source of entertainment — like a darkly amusing TV series that you find out is made from a whole lineup of engrossing books that you at least aspire to read. Such is the case with Slow Horses on Apple TV+, adapted from a series of spy-thriller novels by Mick Herron.

The dozen books and subsequent TV show rise from a complex world of spy circles with Cold War underpinnings leading into and out of MI5. That’s the U.K.’s primary security agency, sort of like the FBI in the U.S. In the story, a dysfunctional team of MI5 agents relegated to “Slough House” become embroiled in matters of national security, often at odds with M15 first-stringers.

Even if you’ve got a good ear for U.K. and European accents, you may still find yourself baffled by the in-jokes, shop talk and slang coming out of the characters’ mouths. Good thing there are helpful reference materials out there, like a whole glossary of terms.

Spy Write fan site: Mick Herron’s Slough House — a Glossary (and more)

Jeff Quest manages Spy Write, a site dedicated to spy fiction and nonfiction in movie, TV and book forms. It features an entire Mick Herron — Slough House section. It includes a list of all the books in order of release, related news about the show, a podcast and, crucially, a glossary.

The glossary is made up of about 110 terms. They cover the characters, settings and slang terms you might come across while reading or watching.

Each glossary entry has initials at the end for the book in which the reference first appeared (e.g., SH for Slow Horses, DL for Dead Lions, SS for Spook Street, LR for London Rules, RT for Real Tigers, TLDL for The Last Dead Letter and TC for The Catch — just to ID the ones in the examples of terms below).

The glossary is an impressive resource you can turn to repeatedly if necessary. It covers a lot.

From the characters you meet, like primary ones played on the show by Jack Lowden, Gary Oldman and Kristin Scott Thomas, respectively (and many others):

Cartwright, River [Lowden] – Young, white, fair hair, grey eyes and a mole on his upper lip. Wannabe super spy/espionage royalty/screwup. In the first book his bungled call on a potential terror incident landed him on the slow horses where he’s been trapped ever since. (SH)

Lamb, Jackson [Oldman] – The famous, or infamous depending on who you ask, Cold War spy. A Cold Warrior whose closest brush with being PC was turning on a computer. Never found a nap not worth taking, belch not worth belching or fart not worth letting loose. The improbable creator and head of Slough House. Worked as a mirror-man in Berlin during the Cold War. (SH)

Taverner, Diana aka “Lady Di” [Scott Thomas] – MI5 upper management. I was going to call her a schemer, but since everyone in these books seems to be scheming in some way, that doesn’t seem entirely fair. Better might be that she raises scheming to an artform. She keeps a finger on all the plotters plots at MI5 with the hope that one of them will propel her to the top job. The iron fist of MI5 who is missing her velvet glove. (SH)

To important places …

Slough House – Located on Aldersgate street right next to Barbican Station in London. It was created at Jackson Lamb’s request after he did the dirtiest of dirty work for MI5. (SH)

Regent’s Park – The main location of MI5. The Holy Grail for all Slow Horses. (SH)

To terms of the trade within the MI5 of the novels …

Black Ribboned – MI5 uses a black ribbon to tie off closed files. Also used as a euphemism for the shipping off of folks to secret black sites in Europe which is the rumored way MI5 gets rid of it’s internal and external personnel problems. (LR)

The Dentists – The MI5 interrogators who go to work in the deniable basement interview rooms. (DL)

The Dogs – MI5’s internal investigation unit. They keep the MI5 employees in line and sweep their errors under the rug. Don’t end up in the lower level in one of their “interview” rooms. (SH)

Stoats – Watchers. Agents performing surveillance on a target. (SS)

London Rules – The rules for survival in the MI5 bureaucracy –

Rule #1. “Cover your arse.” (SH)

Rule #2. “[F]orce others to take you on your own terms. And if they didn’t like it, stay in their face until they did.” (LR)

Rule #3. “[A]lways be a fair distance from a fuck-up.” (TC)

To authentic-sounding terms of trade craft and Cold War-era leftovers …

Cold body – A set of identity papers that is ready to be used and rock solid. Typically created years before they are needed. (LR)

Grey Books – Also known as the “whackjob files.” The files that the government keeps on every crazy conspiracy theory. (RT)

Mirror-man – A sort of spy supervisor who receives updates from agents on encounters with the opposition. (TLDL)

Moscow Rules – The Rules for survival in Cold War Moscow, the main one which is – “Watch your back.” See here for more. (SH)

The Moscow Rules as shown at the International Spy Museum.
The Moscow Rules as shown at the International Spy Museum.
Photo: Jeff Quest@International Spy Museum


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