In the "Anvil of Time," the PCs unleashed chaos which changed the effects of magic going back 70 years, sent them to Tienna's sister planet Allevia (full of strange magic), and now they are seeing the effects of that unleashed chaos 70 years later--in other words, after the societiess have become used to the strange magics. See here: Anvil of Time

Here are some oddities on Allevia related to its setting:

Black Curse or Black Death:  This disease takes over the body in the course of a few days, turning the extremities red and black at first, and then spreading until it makes the person incomprehensible, violent, and then suicidal.  No spells work on it.  The only one knowing the cure is Tenvillah.  It involves using the earthberries and earthsilver (which you have collected) to make a cure.

Angry Earth:  You are safe when there is mist.  When the mist clears, you must be on solid rock to avoid being cursed with the earth.  The danger depends on the color of the foliage.  If they are red, the leaves and branches will turn to sharp bladed spikes.  If they have a brownish tint, they will emanate an evil magic that could take many different forms.  If they have a bluish tint, all they touch will be drained of water--even human flesh--immediately.  If they glow yellow, then touching them is touching poison or acid.  And if they glow black...all the gnomes know is that it is “pure evil.”

Earth Berries:  When you find earth berries on bushes, their effect lasts only for about 10-15 minutes after being plucked from a bush unless preserved in Earthsilver.  They have healing properties but not as powerful as Earthsilver.

Earthsilver:  This is a healing water that looks bluish with a silvery tint.  It heals all wounds instantly but is rare and has no magical properties when removed from whatever spring it sprouts from —- except that it will help preserve earth berries for up to one day.  It will preserve their nonmagical properties even longer. It is mostly found inside caves and in the Underdark.

Earthgold: This is a VERY RARE healing water, similar to Earthsilver but with a brass tinge. Unlike Earthsilver, its effects do not expire unless it is mixed with other ingredients or otherwise spoiled (such as by an improper container, dirt, etc.)

The Source of Magic: Somewhere on Allevia is the "Source of Magic." Finding it and "fixing it" (whatever that means) will reset things to their natural and proper order -- i.e., ending this campaign.