The ball trapped by the first toggle switch, when freed by the next ball through, swoops up and around the corner, down a ramp past the green and red alphabet-block guardrail and drops through a hole into a series of ramps in the pivoting blue page, and then out. Every other ball traveling through the book attempts this daunting passage. Not all manage it. Some get hung up and are knocked through by the next ball. The square holes you see on the left are little passages between pages.