Luc Besson: Scarlett Johansson is perfect on set
19 August 2014 Last updated at 00:16 BST
French director Luc Besson has returned to science fiction with a new thriller starring Scarlett Johansson and Morgan Freeman.
Some of Besson's best-known films include Leon, The Fifth Element, The Big Blue and La Femme Nikita.
In Lucy, Scarlett Johansson stars as a young woman caught up in a dangerous drug deal that sees her inadvertently acting as a drug mule, carrying a substance that gives her superhuman abilities.
Besson told Sophie van Brugen why he wanted to make a "fun" thriller with a philosophical theme.