Your starter for Tenet: the archaeological mystery behind the film of the summer

What is the mystery at the heart of Christopher Nolan’s Covid-defying blockbuster?

The most obvious answer – though, as we’ve found to our cost, it isn’t straightforward – is that Tenet is about time travel, and is based on complicated theories about the manipulation of entropy. Among the most impressive sequences are those in which our heroes, played by John David Washington and Robert Pattinson, are pursued by a car speeding “backwards” through time.

But, as this is a Nolan blockbuster, the riddle runs deeper. And we’re not simply referring to the imponderable puzzle of how Pattinson keeps his hair so magnificently floppy throughout. “All I have for you is a word,” says Martin Donovan’s mentor to Washington’s character, the Protagonist. “Tenet… it will open the right doors, and some of the wrong ones too.”

The first clue is the movie’s title. “Tenet” is, of course, a palindrome. Moreover, the name has been stylised by Nolan in early posters so that the second “T” and “E” at the end are flipped over. Thus the word runs forwards and backwards spatially and graphically.

Nolan has dropped another breadcrumb in naming Kenneth Branagh’s villain Andrei Sator. A “Sator square” is a word square containing a five-word Latin palindrome. The best known examples, discovered in the territories controlled by ancient Rome, spell out “S A T O R” left to right and top to bottom, and “R O T A S” in reverse. Guess what they spell down the middle, left to right, right to left, top to bottom and bottom to top? That’s right: “T E N E T”.

The first Sator square was discovered in the ruins of Pompeii – which feature late in the film. It was unearthed in 1925 on the bathroom wall of a house identified as belonging to one “Paquius Proculu” (about whom we know nothing else). A second was uncovered in the same town in 1936, on a black sandstone plaque near the amphitheatre. Both discoveries were part of a series of excavations by Italian architect Amedeo Maiuri, and are still preserved there today.

Dozens of Sator squares have since been identified around the world, including in the foundations of a second-century Roman fort in Manchester. Another was found scrawled on the wall of the 16th century Church of St Barnabas, in Alphamstone in Essex. They endure to the present, their purpose an enigma. (It is, at least, conjectured that the Essex inscription was the work of Nicholas Le Gryce, rector of Alphamstone from 1576 to 1593, but his motives are unclear.)

The words on the squares are mirror images: “Sator” and “Rotas”, “Arepo” and “Opera”, “Tenet” and (it being the central word of five) “Tenet”. Unsurprisingly, the entire object is generally regarded as a riddle. The Latin translation of the palindromic sentence “SATOR AREPO TENET OPERA ROTAS” – or the inverse, as the word-order doesn’t matter – is: “The farmer [named] Arepo uses [or holds] the plough for work.”

No theory exists as to the identity of “Arepo” – at least, that was the case before Nolan turned up. In Tenet (the film), “Arepo” is the name of an (unseen) art forger whose fake Goyas serve as an early MacGuffin. “Tenet” itself is a code-word for the operation to dismantle the time-inverting technology (and thus save the world). “Rotas” is the name of the company which manufactures the “turnstiles” that allow travel back and forth through time. And “Opera” is where the film opens, with a grand action sequence in which a piece of crucial equipment is retrieved by the Protagonist.

So that’s the surface-level teaser. But if you want to go deeper – and Christopher Nolan would certainly hope that you do – then the puzzle has additional layers. Who, for instance, is the original “Arepo” of the Latin translation? What do “plough” and “work” portend? What of the significance, in particular, of Tenet, which means either “hold” or “use”?

And that’s merely the outer part. Early Christians repositioning the letters around the central “N” found they could spell “Pator Nosta”, meaning “our Father”, in two cross-shapes. Four letters were left over – two “A”s and two “O”s. These, it was posited, stood for “Alpha” and “Omega”, in reference to the omniscience of God.

Such symbology will have chimed with Christians persecuted by the Roman Empire, who identified themselves with secret signs (such as the looping “fish” symbol). Was the Sator square an allusion to their forbidden beliefs?

Some scholars also theorise a connection to the ancient pagan cult of Mithraism. The idea goes back to the discovery of a Sator square at the ruined city of Dura Europos in Syria. Mithraism peaked in popularity in the first to fourth centuries, with worshippers scattered across the world from ancient Rome to India. And guess what – Nolan shot extensively in India, including at the Taj Mahal Palace Hotel in Mumbai and the Royal Bombay Yacht Club.

To return briefly to the Christian association, if you etch out a Maltese cross on the square, going from “A” to “E” to “O” to “N” from all four sides, you get “AEON”, or “an indefinite and very long period of time”. Maltese crosses first began to appear in Europe in the 16th century, and were linked to the Knights Hospitaller (headquartered in Malta) and, later, other military orders across the continent. They are thus a symbol of militarised Christianity.

With so many esoteric subtexts, it’s unsurprising that the Sator square went on to become associated with paganism and magic. The square is sometimes believed to ward off evil spirits, and the internet is full of instructions on how to fashion your own home-made version, the better to keep evil at bay.

Keeping evil at bay is obviously what Tenet is all about, with Washington’s Protagonist zipping across the time-lines to prevent Branagh’s Sator blowing the world to kingdom come. And so, with that case closed, on to the next mystery – how are you going to make it to the cinema in the middle of a pandemic?