New friends Nilly and Lisa help eccentric professor Doctor Proctor to develop his latest invention, a powder that makes one fart, making them very popular at school, but someone is planning to steal the industrial-strength formula for evil purposes.

In nineteenth-century Norway, fourteen-year-old Astri, whose aunt has sold her to a mean goatherder, dreams of joining her father in America.

There are no polar bears left on Bear Island. At least, that's what April's father tells her when his scientific research takes them to a faraway Arctic outpost for six months. But one night, April catches a glimpse of something distinctly bear shaped loping across the horizon. A polar bear who shouldn't be there--who is hungry, lonely, and a long way from home. As their unlikely bond grows, April is determined to save her new friend--and so begins...

Five years after taking Bree and her brother Devin from Ireland to serve as tenth century Viking slaves, Mikkel decides whether to keep his promise to return the pair to their home and restore their freedom.