Living in Tornado Alley can be scary, but twisters aren't as scary for anyone as they are for thirteen-year-old Anna Logan. Normally she's fearless, but the sight of storm clouds is enough to tie her stomach into knots. With no friends she trusts and a family that doesn't allow fear to dwell on its doorstep, she has no one she can talk to. But then Seth shows up at her school, and he's afraid too. Their fear bonds them, and Anna wants to help him move past his fear. But who will save her from her own?

Pearl is the biggest mystery Peter has ever known. She's beautiful, she's quiet...and she might be an alien. Pearl and her brother Axel seem like runaways at first. They're hiding in the Pennsylvania woods, afraid of being discovered. Axel explains to Peter that they don't belong on Earth - they're stranded. They belong on Enceladus, a tiny moon of Saturn, and they want to go back home. It seems believable, but is a vibe coming from Axel that Peter doesn't like. As soon as Peter gets a chance, he turns to run away. But everything changes when Pearl silently asks him to take her with him....