[billybobsky]

interesting idea. my only critique really is that the odor of a decomposing corpse would have been prevalent throughout the apartment building not just the neighbor's abode.

but that leads to an awesome possible plot twist -- the tree has been there forever, cared for by these lonely old people which it consumes floor by floor -- the landlords are in on it, of course and the protagonist doesn't know about it because he hasn't been living there that long and the building has a fairly high turnover except for the elderly...