Kiran Millwood Hargrave

Mila lives with her sisters, Pipa and Sanna, her brother Oskar, and their sled dogs in the forest where winter has held sway for five years, ever since their father disappeared; but now a strange scary man, flanked by twelve young boys, seems to have bewitched Oskar and taken him away--and Mila, convinced her brother is in danger, leads her sisters in a desperate journey across the frozen wild-lands to find their brother, and perhaps a way past an...

"Ten-year-old Julia loves the mysteries of the ocean and marine biology, just like her scientist mother. Her family is spending the summer on a remote island where her mom is searching for the elusive Greenland shark...Determined to prove that the shark is real, Julia sets off on a quest to find it herself, armed with a set of coordinates, a compass, and her trusty rain jacket. She soon realizes that there are some journeys you shouldn't go on alone....