There are precious few directors who are handed over $100 million, let alone $200 million, to make a movie that isn't based on a comic-book, TV series, or existing IP.

Yet, Christopher Nolan's 'Tenet' is now on track to being his most expensive movie ever with a reported production budget of over $200 million - and that's not even counting the marketing budget either. What's more fascinating about this is 'Tenet' is a purely original story, without any existing materials or IP to help sell it.

Variety reports that 'Tenet' now has a $205 million production budget, which is $25 million shy of 'The Dark Knight Rises', his most expensive movie ever. That said, 'The Dark Knight Rises' made over $1 billion, so there's reason for that trust. In fact, the nearest comparison to 'Tenet' would be 'Inception', which cost $160 million and ended up making $828.3 million at the box office.

Like 'Inception', nobody has a clue what 'Tenet' is about and the promotional campaign is taking great pains to ensure you're going into the cinema basically blind. The teaser that debuted last month only gave small clues as to what it's about - something to do with reversing time? - while the IMAX preview that was attached to 'Star Wars: The Rise of Skywalker' was a 6-minute scene without any context.

Speculation is that 'Tenet' is a sequel-of-sorts to 'Inception', but again, that's just speculation as nobody really knows what the movie is about.

Imagine that, though. A movie costing over $200 million and nobody has a clue what it's about. It's not based on anything, it's not a sequel to anything (we think), and it's got that kind of budget.