10 Movies That Were Filmed In Total Secrecy

10. 10 Cloverfield Lane

In a virtually unprecedented move at the time, Cloverfield spin-off 10 Cloverfield Lane was announced less than two months before it hit cinemas, by which point it was already deep in the final stages of post-production.

Always one to love a mystery, producer J.J. Abrams had the movie shot under the unassuming title "Valencia," and it was only during production that he committed to giving the low-budget sci-fi monster movie an immediate tie to Cloverfield.

This was covert enough that even two of the movie's stars, Mary Elizabeth Winstead and John Gallagher, weren't aware of exactly how intimate the link between the two films would ultimately be, and Abrams only came up with the final title shortly before the first trailer dropped.

As much as Abrams' love of the "mystery box" can frustrate, this was an undeniably genius feat of covert filmmaking and "gotcha!" movie marketing.