The story of the film is based on Carrie Ryan's best-seller, which is set sometime in the future and where most of the human race has been taken by a bloodthirsty virus that leaves them roaming the planet as cannibals, reported Variety.
Mary, played by Williams, leads a group to throught the dark forest and the survival of the humanity depends on the success of her mission.
Williams was most recently seen in famous British show "Doctor Who".
