Fifty winters ago, Elizabeth and Simon fled war-torn New Haven City into the Emerald Mountains, where a dwarf named Taproot used his powers to shrink the two children. These new "one-spirit" beings, Elsbeth and Sim, master that same magic and create others like themselves. They live in underground burrows, dump-dive for supplies, and chat with animals. All, under the watch of Taproot and the regal Pensworthy owls. But Sim The First Father believes rules don't apply. One rash decision leaves him and three clan members wandering the treacherous, icy passes. Can Elsbeth The First Mother dig within to help Sim, herself, and the clan?