Horzine Outbreak is based on original Killing Floor mod (KFMod) v1.0 for Unreal Tournament 2004 by Alex Quick and tell a story about incident in Horzine Biotech, currently in progress and being made by the last version of Xash3D + XashXT.
You are security officer in Horzine Biotech corporation in London. You dont care about what do these scientists, because you earn much for your work. Until... the light flickers and you hear panic screams in the radio and chaotic shooting...