Great. After you wiped the evil demons off the earth and hell(you think), strange things start happening at UAC. Something has gone wrong there and it turned all the marines against you. You know that UAC has all the weapons from the lowly pistol to the awesome BFG9000, and this strange new weapon the shoots fireballs which you don't ever get(sorry), so some marines will be very dangerous, especially the ones with BFG9000s! You are determined to get to UAC headquarters where the source of the problem is and stop it. Could it be some hellspawn that somehow has survived? Only you can find out, your life depends on it!
MAP01, MAP02, MAP03