If you like Down to the Wire by Shannon Greenland

If you like Down to the Wire, you may like other titles in the Specialists series. They include Model Spy, The Winning Element, and Native Tongue, all by Shannon Greenland.

The White Darkness by Geraldine McCaughrean.

Taken to Antarctica by the man she thinks of as her uncle for what she believes to be a vacation, Symone--a troubled fourteen year old--discovers that he is dangerously obsessed with seeking Symme's Hole, an opening that supposedly leads into the center of a hollow Earth.

The Sisterhood of the Traveling Pants by Anne Brashares.
Four best girlfriends spend the biggest summer of their lives enchanted by a pair of magical pants.

H.I.V.E. : Higher Institute of Villainous Education by Mark Walden.
Swept away to a hidden academy for training budding evil geniuses, Otto, a brilliant orphan, Wing, a sensitive warrior, Laura, a shy computer specialist, and Shelby, an infamous jewel thief, plot to beat the odds and escape the prison known as H.I.V.E.