Alien is an action/horror film series created by Dan O'Bannon and Ronald Shusett. The series began with the four films Alien (1979), Aliens (1986), Alien 3 (1992), and Alien Resurrection (1997). A prequel series directed by Ridley Scott began with Prometheus (2012) and continued with Alien: Covenant (2017). Set between the 21st and 24th centuries, the plot focuses on humanity's violent encounters with a vicious alien life form, with the lead protagonist being Ellen Ripley, a woman determined to stop the creature and prevent the corrupt Weyland-Yutani Corporation from obtaining it for biological weaponry.