((it's easier to be better. All you have to do is be descriptive. It's just like Kaj says. if you try that, it turns out more full and formed then those mini-posts. I'm a writer too, and I think if you put a little more effort into it it would help the overall quality of your posts. Here, I'll throw you a bone with the growths.))
He led them through a several intersections, then into an antechamber. It was at this point he raised his flashlight to see which entry was the right one. there were 6 passages, all of them old and wor like some ancient edifice. the edges of the walls that had become visible had been covered in grotesque carvings of some dark design. Growing over them, consuming the lichen that encrusted the surface, was a living substance that could be only described as a slimy, semi opaque 'growth'. It seemed like living tissue of some form, since it had pulsing veins running through it.
He was actually quite afraid. That growth, as he remembered it, was only patchy, save for in old town, where it had been flourishing fr the last couple of weeks. So far as he knew, only him and the prof knew about the strange substance. He spoke to himself in a half concerned, half analytical voice, "Hm...it's this far now? Troublesome... I wonder what prof would say..." before turning and addressing the ones following him. He kept his flashlight down as per his usual. "Alright, follow my light....try not to touch the walls from here on out, ok?" He walked forward into one of the passages, then waited for them to follow, wondering what old town's section looked like by now. He shrugged, he'd find out soon enough. The university was in the center of old town anyway.