After being shipped off to stay with her aunt and uncle in Nowheresville, Pennsylvania, city girl Effie Starr Zook stumbles upon a mystery that leads her to an old family feud in this "accessible and exciting" (School Library Journal, starred review).

A rich girl from New York City, Effie Starr Zook isn't afraid of much. When her parents go on a dangerous round-the-world adventure in a solar airplane, she's packed off to her aunt and uncle's farm for the summer. Expecting boredom, she runs smack dab into a family secret. Why does the neighbor kid want to avoid her? What are her...

Twins Mark and Scott discover an abandoned Apollo command module and take off to rescue a stranded Russian cosmonaut in the second Astrotwins adventure from retired NASA astronaut and the #1 New York Times bestselling author of Mousetronaut, Mark Kelly.

Mark and Scott Kelly, who are mostly known for getting into trouble, are finally back from their first space adventure. The twins have wanted to explore space ever since they were little and watched Neil Armstrong walk on the moon. And when they hear that a Russian cosmonaut is trapped inside the Salyut space station now...