Tome of Clear Thought

Tomes of Clear Thought are magically tomes that increase the primary ability of intelligence by one point and are consumed when the point is added. One tome of can be found in the cave in the area with the lighthouse.

In-game description
"A typical tome of clear thought contains a collection of esoteric and sholarly literature, often involving obscure mathematical or algebraic formulea or the occasional reference to inter-planar biology. Such tomes are usually magically enhanced, thereby allowing an individual to raise his or her Intelligence by a single point. Unfortunately, the manual will dissappear after a single use."