Scarlett Johansson's action girl credentials are about to get a big boost - she's close to signing on for director Luc Besson's next movie. The Frenchman behind the Transporter and Taken franchises has cast the actress in Lucy, a new film he has also written. In the movie, Besson's leading lady becomes a fighting machine when a drug she is carrying for a ruthless crime boss leaks into her system.