In Killing Floor 2, players descend into continental Europe after it has been overrun by horrific, murderous clones called Zeds that were created by rogue elements of the Horzine Corporation. The Zed outbreak caused by Horzine's failed experiments has quickly spread with unstoppable momentum, paralyzing the European Union. Only a month ago, the first Zed outbreak from the original KILLING FLOOR ripped through London; now the Zeds are everywhere. Civilization is in disarray, communication networks have failed, governments have collapsed, and military forces have been systematically eradicated. The people of Europe are now focused on self-preservation, the lucky few who survived having gone into hiding.

But not all have given up hope; a motley group of civilians, soldiers, and mercenaries have banded together to fight the Zed outbreaks from bases across Europe. When an outbreak is detected, the players are sent into Zed-laden hot zones to exterminate all threats using whatever means necessary. Welcome to the Killing Floor.