Look up—into the blue and beyond. What do you see? The sky—our atmosphere—may seem empty or invisible. But is it? Using spare, lyrical language, author Lydia Lukidis (Deep, Deep Down: The Secret Underwater Poetry of the Mariana Trench) takes readers on an imagined journey up, up high to discover the surprising and wonderous things flying, floating, and happening between the treetops and the stars in this STEM-based picture book.