Daybreakers

Daybreakers is a 2009 Australian-American Science Fiction horror/drama film where by 2019 most of the population are Vampires who require human blood to live lest they become horrid bat creatures known as 'subsiders'. The protagonist is vampire hematologist, Edward Daltan, who works for a company that while providing most of the US with blood is looking into a blood substitute. A project Edward is involved in, however his work is interrupted by 'Elvis' a former vampire who has a cure that can save humankind.

Plot
It is 2019. A plague has transformed most of the world's population into vampires. The human population has plummeted and the need for blood becomes desperate. Vampires deprived of blood for a long duration degenerate into "subsiders," psychotic bat-like creatures with no memories of who they were and whose only thought is the craving for blood. The few remaining humans are captured and harvested in laboratory farms while scientists research a synthetic blood substitute.

Edward Dalton is the head hematologist for the largest supplier of human blood in the US, owned by Charles Bromley. Edward and colleague Christopher Caruso are developing a blood substitute.

Driving home from a failed experiment, Dalton accidentally runs another vehicle off the road. Checking on the occupants of the other vehicle, he learns they are humans. With the police approaching, Dalton has them hide in his vehicle. They part ways, but not before their leader, Audrey, learns Edward's name and occupation from the ID badge on his jacket.

At home, Edward is surprised by his estranged brother Frankie. Frankie's gift of a bottle of pure human blood re-ignites a long-standing argument over Edward's sympathies towards humans. The argument is cut short when a subsider invades Edward's house, forcing the brothers to kill it.

The next morning, Audrey visits Edward's home and hands him a note with instructions for a meeting. During the meeting, Edward is introduced to Lionel "Elvis" Cormac, another human, but is interrupted when a military team arrives with Frankie, who had followed Edward and intends to capture both Cormac and Audrey, however, Audrey manages to knock Frankie unconscious and the three flee. Once they escape, Cormac reveals that he was once a vampire. He was cured when a car crash ejected him from his sun-proof vehicle. Because of his exposure to the sun, Elvis burst into flames, but his life was saved when he landed in the river, having been exposed to the sun for a precise length of time to turn him human again. Edward agrees to help Cormac find a way to recreate the cure.

That night Edward meets more human survivors, as well as Senator Turner, a vampire who is secretly helping the colony develop a cure. A convoy of humans heading to Audrey's group is ambushed and captured. The soldiers track the position of the vineyard, forcing Turner and the humans to flee. Audrey, Cormac and Edward stay behind so Edward can be cured. Edward is able to recreate the cure Elvis had explained, curing himself of vampirism. They attempt to regroup with Turner and the other humans, only to find they are all dead.

One of the captured convoy, Alison, is revealed to be Charles' human daughter. Charles has Frankie forcibly turn her into a vampire. She refuses to drink human blood, and turns into a subsider. She is rounded up with others and dragged into sunlight to burn to death. Witnessing Alison's death upsets Frankie, causing him to seek out his brother. Meanwhile the military imposes martial law to control the subsider population and preserve order.

Edward, Cormac and Audrey break into Christopher's home and ask him to help spread the cure. However, Christopher has finally discovered a viable blood substitute and is not interested in a cure. He summons soldiers who capture Audrey while Cormac and Edward escape. They are found by Frankie, who agrees to help. He attacks Cormac, but drinking his blood turns Frankie human again as feeding on a cured vampire also turns them into humans.

Edward, trying to save Audrey, turns himself in to Charles. After listening to his plans of creating a monopoly with the blood substitute, Edward taunts Charles who becomes human again after biting the cured Edward.

Edward leaves Charles at the mercy of soldiers about to become subsiders. Edward and Audrey are rescued when Frankie allows the troops to drink his blood which sparks a feeding frenzy. Christopher arrives, seeking to cover up the cure by executing both Edward and Audrey; however, he is mortally wounded when Cormac shoots him with a crossbow.

The three survivors drive off into the sunrise, with Edward in a voice-over stating that they have a cure and can change others back.