A fast-paced middle school mystery about a hidden agreement that could change everything.

When a sealed annex at Brackenridge Middle School is quietly reclassified, most students ignore it.

Tamsin Sloane does not.

A cracked courtyard slab. A buried ledger. A trust agreement no one was supposed to see.

What begins as after-hours curiosity turns into a race to uncover a secret property deal tied to land the school was never meant to control. The deeper Tamsin, Callum Ridge, and Ravi dig, the clearer it becomes: someone powerful wants the truth to stay buried.

Now they are facing:

• A sealed school record
• A hidden land transfer clause
• A rushed administrative hearing
• And adults who are not telling the whole story

Every clue raises the stakes.

Every discovery brings consequences.

Perfect for readers ages 9-14 who love middle school mystery books, school-based mysteries, and smart kids uncovering secrets adults try to hide.

The Secret Under the Annex is part of the Middle School Mystery Series-stand-alone, high-intensity mysteries featuring new schools, new characters, and new secrets in every book.