A haunting tale of love and mystery from the New York Times bestselling author of Bird Box and Malorie.

At seventeen years old, James and Amelia can feel the rest of their lives beginning. They have got this summer and this summer alone to experience the extraordinary.

But they didn't expect to find it in a house at the bottom of a lake.

The house is cold and dark, but it's also their own.

Caution be damned, until being carefree becomes dangerous. For the teens must decide: swim deeper into the house-all the while falling deeper in love?

Whatever they do, they will never be able to turn their backs on what they discovered together. And what they learned:

Just because a house is empty, doesn't mean nobody's home.