10 Movies That Were Shot In Secret

David Lowery's supernatural drama A Ghost Story is an interesting example because it was shot in secret precisely because the filmmaker himself didn't know how it would turn out.

The left-field drama about a man (Casey Affleck) who dies and becomes a ghost who lingers in the house he shared with his wife (Rooney Mara) was produced for just $100,000 and filmed quietly in the Irving-Dallas area near where Lowery grew up. 

Its existence wasn't confirmed until November 2016, some five months after Lowery shot it, which by his own admission was because he didn't know if the idea would actually work, or if it would even turn out to be a feature film.

Even Affleck and Mara's agents didn't know about the shoot until just before it took place.

Furthermore, the low budget was financed entirely by Lowery and his producer Toby Halbrooks, to ensure that even if it didn't work and never saw the light of day, the damage would be minimal.

But ultimately A Ghost Story premiered at the 2017 Sundance Film Festival to rave reviews, and ended up grossing $2 million at the box office. A mighty return on something that could've never seen the light of day, then.