Anónimo

Nancy's classmate, Willa, needs her help. Willa is convinced something is terribly wrong with her friend Izzy, but everyone has dismissed Willa's concerns, saying it's just teen angst. But Willa thinks it's more than that; she thinks Izzy is possessed. It all started when Willa and Izzy snuck into an abandoned house with some of their friends. After running around and exploring, Willa went in to the basement and found Izzy staring into space. Izzy was conscious, but she was acting weird - she wouldn't speak and she didn't seem to recognize Willa.

When summer comes around, it's off to the beach for Rosalind...and off to Maine with Aunt Claire for the rest of the Penderwick girls, as well as their old friend, Jeffrey. That leaves Skye as OAP (oldest available Penderwick)—a terrifying notion for all, but for Skye especially. Things look good as they settle into their cozy cottage, with a rocky shore, enthusiastic seagulls, a just-right corner store, and a charming next-door neighbor. But can Skye hold it together long enough to figure out Rosalind's directions about not letting Batty explode?

Tensions are running high when multibillionaire Lars Sjoburg is poisoned and demands to go home, and everyone is looking to Dash Gibson to solve the case in this third and final book in the New York Times best-selling Moon Base Alpha series.