Ang Lee's sci-fi thriller has Smith playing dual roles: an aging assassin hunting down his younger clone. The movie uses the kind of de-aging special effects used in "Captain Marvel" to make the 50-year-old Smith look just like he did when he was 23.
"They chose me because there's never been anybody like me," the older assassin, Henry, tells "Junior." Their cat-and-mouse game is complicated by the fact that they can predict each other's moves.
The story bears similarities to Rian Johnson's "Looper," which featured Bruce Willis and a younger version of his character played by Joseph Gordon-Levitt. But that involved time travel, while this movie uses cloning.
And now, the technology has improved enough that Samuel L. Jackson was very convincing as a younger, '90s-era Nick Fury. Martin Scorsese is also using de-aging VFX in his upcoming "The Irishman" so that Robert De Niro and Al Pacino can play characters through multiple decades.