Some of theme were used as bomb shelters, others for logistics, bunkers, warehouses and secret laboratories. Now the government sustains just a few of them and many are abandoned or buried. And when it comes to them, everyone is silent...

Recently, in an old military apartment building in the center of Sofia, under the foundations of which the legend says that there is a laboratory for biological experiments with people from the dawn of socialism, something terrible happened. A group of adventurers disappeared, no traces were found, except for an open old ventilation shaft.

What had happened? Rumors speak of mutated creatures - the result of experiments conducted in the laboratory, that were later released!

Deep in the catacombs below Sofia grows an unknown, distinct life… Which will prevail, the fear or the curiosity?

Would you dare to step inside?