level 18 party?
Get 2 sor or wiz that can cast dispel magic, make a lot of scrolls, and have them be improved invis.
Start casting dispel magic on everyone until all items are inert.
Force a fight where their magic items don't work and spells are being targetted by wands of dispel magic to counterspell (still invisible)
The fight has creatures that mixes spell casting and fighting. This should confuse the players into not realizing there's more npcs out there.
Dwell into the past of these people, one of their enemies that hasn't re-occured in a LOOOOOONG time. That's because he's been scrying and spying and watching and learning what he can of the pcs. What are their strengths and weaknesses. and uses it trully against them.
Have a rogue replace the cleric's holy symbol sometime before this encounter and make all of his spells fizzle for no reason. (make sure that spells that need a divine focus don't work, all else does, but don't tell him that) If the cleric should ask what's happening with his spells, you answer back "you are unsure, you feel strangely out of synch with your deity".

Get 2 sor or wiz that can cast dispel magic, make a lot of scrolls, and have them be improved invis.
Start casting dispel magic on everyone until all items are inert.
Force a fight where their magic items don't work and spells are being targetted by wands of dispel magic to counterspell (still invisible)
The fight has creatures that mixes spell casting and fighting. This should confuse the players into not realizing there's more npcs out there.
Dwell into the past of these people, one of their enemies that hasn't re-occured in a LOOOOOONG time. That's because he's been scrying and spying and watching and learning what he can of the pcs. What are their strengths and weaknesses. and uses it trully against them.
Have a rogue replace the cleric's holy symbol sometime before this encounter and make all of his spells fizzle for no reason. (make sure that spells that need a divine focus don't work, all else does, but don't tell him that) If the cleric should ask what's happening with his spells, you answer back "you are unsure, you feel strangely out of synch with your deity".
