What is going on on the set of Christopher Nolan's super-secret movie?

Theories are already flying round the internet about what director Christopher Nolan’s new film Tenet is going to be about – and now a video captured by an onlooker in Estonia have prompted more speculation.

The clip in question, reposted by tweeter ibabysky (from the Instagram feed of Tallinn resident @niinapotapski) shows a road with all the cars driving backwards. Two onlookers watch the proceedings from a nearby car park.

Niina Potapski captioned her Instagram “Estonian racing... Christopher Nolan’s film "Tenet" is being shot in Tallinn... Filmed the clip from out of our flat window.”

It’s left fans convinced that the director of Inception and Memento is up to his old tricks. In both of his earlier films, he reversed elements to enhance the story. The fact that the film’s title Tenet is a palindrome, reading the same backwards and forwards, has only bolstered the theories.

Read more: Chris Nolan’s ‘Tenet’ could be one big palindrome according to this fan theory

One eagle-eyed tweeter did have another idea however. @hukestage thought that the video actually captured the stunt drivers returning to their starting positions between takes. @He tweeted his theory, saying, “crying at everyone thinking this is gonna be in the film.”

But @ibabysky has posted a second video (credited to @kevinuks), which suggests this hunch could be incorrect. In the second clip a helicopter can be clearly seen filming the cars travelling backwards.

Nolan has been his usual secretive self about the project. In fact, news only started to drip through about the production back in March, when the leads John David Washington, Robert Pattinson and Elizabeth Debicki were announced.

Warner Bros then revealed the attachment of Aaron Taylor-Johnson, Kenneth Branagh, Michael Caine, Dimple Kapadia and Clémence Poésy to the project and the film’s title later in May.

Read more: New details for Christopher Nolan’s super secret upcoming movie emerge

The new videos were filmed in the suburb of Lasnamäe in the Estonian capital, where Nolan and his cast and crew have been shooting this week. Debicki and Pattinson have both been snapped on set by local news outlets. The Guardians of the Galaxy actress has been seen dressed all in red, with Pattinson seen stalking around in detective-like apparel.

Tenet currently has a release date of July 17, 2020.