Aachen - last place of refuge

The world is doomed! A zombie-apocalypse broke out. An experimental virus already infected about 93% of earths population and turned peacefull humans into hungry canibalistic undead. There is no safe place - almost. Rumors say that a small german city called Aachen managed to create a last place of refuge for survivors to outlast the dangers the undead-terror. Sadly the city is called to high security measures for it to stay a safe haven. Every group of survivors has to undergo a test to prove themselfes not infected. You survived and are surely not infected? Prove it by passing our test-chamber and finally gain entrance into aachen - the last place of refuge!