One of the scientists points out that a time-traveling device called the Time-Lock was found in the Sirian ruins. Mental's forces are invading Earth, humanity's last stronghold, and there's no way to stop him. One of the heroes during these battles is Serious Sam, who constantly and ruthlessly fights off every alien he encounters.Īfter many battles, humanity is now doomed. His power and craziness earns him the name 'Mental'.

After being woken up, Chaad Sheen manages to defeat the humans, one battle after another. He decides to go through it, which was actually an ancient alarm system for Chaad Sheen designed to wake him up as fail-safe in case he hadn't exterminated all intelligent life in the universe. While exploring Sirius, Sam 'Serious' Stone, a Captain in the Earth Defense Force, discovers a large asteroid belt surrounding the planet that was never mentioned in the old Sirian archives. Humanity ignored the Sirian's warnings about Chaad Sheen and traveled through the universe with technology based on a Sirian spaceship that was located on one of Saturn's moons the SSS Centerprice. However, they were wiped out by a mysterious being called Chaad Sheen, who apparently appeared in the universe in order to wipe out all intelligent life once every 100,000 years. This technology is from the Sirians, an extinct species that were quite similar to humans. In the near future, humanity has uncovered advanced alien technology in Egypt which has allowed humans to travel into the farthest reaches of space.

Serious sam 2 walkthrough