The Glass Wall Dilemma

Night swept over the balcony, and a king knows when to pull back into his inner sanctum. I marched straight toward the sliding door to re-enter the fortress, but thunk! My snout slammed directly into an invisible shield of cold glass. Gwah! Trapped outside by an impenetrable wall? Never! I planted my clawed feet hard into the aluminum track, took a breath, and dug my stout fingers into the rubber door seal. With a furious grunt, I threw my spiked shell forward with all my might. Squeeeak—the glass slid open three glorious inches! I swaggered right inside and stood tall.