When ten-year-old Casy arrives at her grandparents' isolated beach house on the Oregon coast, she expects a quiet, forgettable summer surrounded by fog, crashing waves, and endless silence.

Instead, she finds a house that whispers at night.

Behind a locked door beneath the staircase, something ancient waits beneath the cliffs-something tied to the sea, hidden for generations, and buried deep below the foundations of the old Victorian home.

As strange footsteps echo beneath the floorboards and a mysterious map leads her toward a secret chamber under the house, Casy discovers an artifact known only as the Heart of the Reef.

She should have left it alone.

Now, the ocean seems to breathe inside her. Objects move when her emotions spiral. The wind answers when she calls. And somewhere beneath the cliffs, something has awakened alongside her.

But the deeper Casy digs into the secrets surrounding the reef, the more she realizes her grandparents have been hiding the truth for years.

And some secrets were never meant to surface.

Little Girl: The Heart of the Reef is a dark middle-grade fantasy mystery filled with hidden chambers, coastal folklore, supernatural power, and eerie oceanic atmosphere-perfect for readers of Coraline, City of Ghosts, and The Ocean at the End of the Lane.