The Secret on Riverwind Road — Larry Long

Lyle Kincaid comes home from college with two goals for the summer: finally winning the love of his childhood sweetheart and joining his neighbors in sending a rapist-murderer to the electric chair.
When he arrives in tiny Riverview, Iowa, for vacation, the accused killer's trial is six weeks away. The community, including Lyle, is teeming with outrage, demanding swift retribution. But then Nadine Lopez, the Mexican beauty whom Lyle has adored all his life, shares with him a secret known only to one other white man: a secret about who she really is, where she really lives and an extraordinary world that history has overlooked.
That information, conjoined with Nadine's character and grit, soon changes everything Lyle knows about the crime, about his hometown and about himself.
The two twenty year olds struggle throughout the summer, not only on behalf of the accused young killer, but also against demons that prey on lovers from different worlds. The experience will guide them both for the rest of their lives.