Attack!

For years, scientists have played around with teleports and such, but now, one scientist, considered to be insane, has made what we thought was mad. He found a gateway between time, a "Time Slip". This allows you to travel back in time, and then come back to where you began, walk into the time slip chamber, press the button, and ZAP! you're back in the present. One problem. The teleports, as you may know, (if you read readme.exe in Doom) have unleashed some of the most hideous creatures ever. Those cannibal mutations are getting through the teleport statios, and entering the "Time Slips". Since then people have been disappearing rapidly. So has some shops and buildings. The Demons must be killing people in the past, which is effecting the future. A Marine, like you, is sent to spy on the enemies. He was killed and hung by a chain, as his last words were: "You b*st*rds! [click click] What? [more clicking] Oh sh*t! My gun...get away from me with that!! [clanking of chains and choking noises] Please!" [transmission cut] That spy was useful, though, he told that they had a whole castle under control. They've put up glass windows to check on the prison cells without trouble. They've through of everything. Except for the fact that someone can get to them through the time slip. You are sent through the time slip, and are to destroy these hellspawns. Your main task is: Attack! (See end of Text for Mission 2 story)