Finally back in print! Venture to save Dr. Vivaldi in this iconic interactive book where YOU decide what happens next. Packed with 21 possible endings! Choose Your Own Adventure books—the 4th bestselling children’s series of all time—are back and as much fun as you remember. Kids and adults agree, these are the books that get 9- to 12-year-olds reading. Your friend, a famous scientist, has disappeared down the bottomless crevasse in Greenland that she discovered. Now you’re a part of the team going down to try to find out what happened. Upon arrival at the underground kingdom, danger and awe are all around you. The choices you make could end up with you caught between warring nations or getting attacked by beasts. Can you make it back to the surface of Earth? Stories of a hidden world beneath our own have long been popular, but in Underground Kingdom, you get to make the choices that guide your time exploring it. Readers looking for an exciting, heart-pumping adventure—buckle up!