Through the Hidden Door (Point Fiction) by Rosemary Wells - Vintage Paperback

"We don't like whiners, tattletales, toadies, or stool pigeons here at Winchester."

Barney's at a school where no one plays fair --- not even the Headmaster. Barney knows he should leave Winchester Academy before he gets hurt. But there's something making him stay.

Day after day, a strange younger boy, Snowy Cobb, leads him blindfolded to explore a vast hidden cave. Together, they have discovered a hidden treasure that no one else has seen for generations-maybe even thousands of years. Snowy wants to keep the cave a secret, but danger is all around. How can they keep such an extraordinary discovery to themselves?

"Wells has written a riveting psychological thriller."-Booklist, starred review
"A satisfying thriller where the nice guys come out ahead."-Kirkus