Day 4, Evening: Brogg's Prayers
You do.
Have you cast out any spells since last you memorized? For *each* spell you need to rememorize, you have to make a WI check at -(3* circle). If you don't remember or want to bother going to look back at previous posts to figure out which spells you've cast, well neither do I. In this case, just randomly remove half your spells and try to get back the others.
The force of Grisbane is pretty weak here, in other words.