Reese Witherspoon and Robert Downey Jr. to Fight Aliens in 'The Days Before'

Two of Hollywood stars, Reese Witherspoon and Robert Downey Jr., are likely to share screen in "The Days Before". According to Production Weekly, the "Four Christmases" actress and the "Iron Man" actor are showing interest in the action sci-fi project, in fact they are in talks to star in it.

While it has been reported that the movie will chronicle a man's attempt to convince the world that the end is coming as aliens invade the Earth, it is still unclear on the potential characters Witherspoon and Downey Jr. are negotiating for. Still, there's a chance that they will work together with "Wanted (2008)" helmer Timur Bekmambetov, who is also reported to be in negotiation for the directing part.

"The Days Before" will have "300" producer Gianni Nunnari serving as its producer. The film's screenplay is provided by Chad St. John. It will tell that a race of aliens will be invading the Earth by traveling backwards through time and wiping out humanity, one day at a time, yesterday by yesterday. Trying to save mankind, one man attempts to stay "a yesterday ahead of them".

Academy Award-winner Reese Witherspoon has been known for her works in multiple films, including "Legally Blonde", "Walk the Line" and "Rendition". She will next be heard voicing Ginormica in "Monsters vs. Aliens". Meanwhile, Robert Downey Jr.'s movie credits include "A Guide to Recognizing Your Saints" and "Tropic Thunder". He is currently involved in "Sherlock Holmes" and is expected to reprise his role of the iron-suited superhero in "Iron Man 2".