The Terran Dominion, now under the control of Emperor Valerian Mengsk, was going to send a small colonial expedition outside of the Koprulu Sector when something went totally wrong and the entire Expedition - along with an observing Emperor Mengsk and his Guard - is sent to a whole new universe with the new baseline of technology called the Mass Effect. Still, the people of this new universe are not ready for a group of people who have literally walked through hell to survive, hence from Hell they have come and they are not happy at all!