The moment Pumpernickel stepped onto the bridge of Glass-Glass, his boots turned the color of thin air. He was a Secret Explorer, leading a band of invisible friends who only communicated by tapping each other’s shoulders. They were hunting for the Heart-Promise, a treasure said to be hidden beneath the feet of giants. Pumpernickel held his breath, feeling the cold, smooth surface of the bridge through his wool socks. He wanted to be the first to touch the prize and bring it home to show he was the bravest of all.