Originally Posted by The Narrator

Spring is on its way, a time associated with new, flourishing life. In the greenhouses, however, only one thing is thriving. The sole surviving vined plant housed here has reached maturity, and is suddenly unrecognisable as the plant it once was.

This plant is glowing now too, though much brighter than any of the dead or dying plants around it. Surely not a coincidence that this occurs just as those pesky vines around Hogwarts grow more active.

Perhaps you noticed all this in the past day or so, but if you were thinking of checking in on these plants now, you're out of luck. The greenhouses are no longer accessible; a thick, toxic fog now settles in around the area. Even the acrid smell warns of danger, and magic does nothing to help breach it.

Steer clear of the fog, if you know what's good for you.