Plague is an illness that is especially frustrating for mage-based characters. It lowers the Strength statistic by 10 points and therefore lowers their carrying capacitity. In the end it can make a weak character not be able to move because of their overloaded in inventory.
The Cure Plague Potion is known to cure it. Despite it's description the Dispel Potion doesn't work.
Another temporary way to live with the Plague is to cast the Feather spell or drink Feather Potion, but it is only temporary.
Throwing down[]
This strategy links to UFO game- in orger to prevent treachery of your fighter with Brainsucker you should drop fog grenade (it only stuns humans but kills aliens), main advantage is that does not require any move, only the priority.
In this game go to inventory, click heavy unvielded item (but keep mortar/prestile) and click arrow keys to remove overload. Main reason is to prevent overload penalty.