Even if it's not told I see that this video is a parody of old movie series called Alien. The main heroine that is going to be fucked by a scary alien is Ellen Ripley. The story is situated somewhere in the space ship and the crew is performing sexperiments on Ellen. She's inside a separate room and the crew lets that horny alien inside. She wants to get outside, but nobody lets her out. Alien comes from behind and puts his huge penis inside her ass. After a while, they switch into a doggy-style position and the alien keeps fucking her tight asshole. Then she lies totally on her stomach against the floor and the creature keeps fucking her ass until it cums and screams from ecstasy as it cums inside her ass.
This video is something similar to the previous video from this author (S&V Productions) - Damnation. Lara Croft gets captured and brought on the board of some spaceship. As I understand the name of that spaceship is Damnation. She's having sex with few guys. In the end, she handles both of them at the same time and they cum on her face. Later on, there come 3 big aliens and they prefer anal sex. So Lara gets fucked by them. Also, some other girl appears who is being sexually tortured by those aliens. Some of them have really huge animal cocks, so they are kinda experimental results of something. The author says that this is a combination of two videos - two parts of Damnation (2nd and 3rd). In the end, an alien cums inside Lara.