Wizard's Notebook

The notebook is filled with arcane formulae, sketches and notes. The last page reads: "Problem: the fools I summon keep trying to leave the castle, while uninvited fools keep trying to sneak in. Solution: a portal maze. A fool who doesn't know the way can keep wandering forever. Observation: fools tend to rush forward blindly. A fool might be so dazzled by an opportunity right in front of him, that he would never think of turning around and looking behind his back. Amended solution: anisotropy and nonlinearity of portal pathways. A to B does not mean B to A!"