Eleven-year-old Merrily is a Montana farm girl who is afraid of flying, deep water and heights. One December night, she discovers a shimmering ladder in her backyard that stretches up as far as she can see. The last thing she wants to do is climb it. But when her brother’s mitten flutters to the ground, she knows she has to go after him. Miles may believe he’s a superhero, complete with a cape and theme song, but he’s only four. And it would only take one slip.