The Friend of the Family by Dean Koontz

The human “oddities” in the Museum of the Strange are less wondrous than the gawking rubes had been promised. But Alida is something else. The real thing. Traveling Depression—era America from carnival midways to speakeasies, Alida is resigned to an exploited and lonely life on the road as the museum’s golden ticket. Until she’s rescued by two compassionate strangers.

Franklin and Loretta Fairchild see in Alida a gifted and uncannily well—read girl in need of a loving touch and a family. With the openhearted couple and their three precociously imaginative children, Alida finds it. Yet despite everyone’s overwhelming generosity and acceptance, Alida knows she is still a very different kind of girl. Her dreams bear that out. They’re vivid, unsettling, and threatening. Alida fears that they’re also warnings. And that it’s the Fairchilds who may need rescue from a bad, bad world.

Alida will do anything to help those she now holds nearest and dearest. Empowered with a purpose to vanquish evil, she will not fail her family.