From the New York Times bestselling author of Bird Box comes a haunting tale of mystery and love, as a boy and a girl on their first date discover a strange house at the bottom of a lake--and a secret that will change their lives forever.

So many love stories begin like this: It is summer. It is a beautiful night at a lake in the woods. They are seventeen. And it is their first date.

But no other love story ends like this.

For Jim and Amelia find something even stranger and more magical than first love: Under the water and in the darkness, there is a house at the bottom of the lake.

They can't resist exploring it. What they find seems to be an ordinary house like any other on any street in their little town . . . except that it is underwater.

But there is something inside it. Something that calls to them. Something that is telling them to come home . . .