From the back cover:
". . . Travel writer Lea Sutter finds herself on a small island off the coast of South Carolina, the wrong place at the wrong time. A merciless, unanticipated hurricane cuts a path of destruction through the island and Lea barely escapes her life.
"In the storm's aftermath, she discovers two orphaned boys - twins. Filled with a desire to do something to help, to make something good of all she witnessed, Lea impulsively decides to adopt them. The boys, Samuel and Daniel, seem amiable and immensely grateful; Lea's family back on Long Island - husband Mark, a chld psychologist, and their two children, Ira and Elena - aren't quite so pleased. But even they can't anticipate their true nature - or predict that, within a few weeks' time, Mark will wind up implicated in two brutal murders, with the police narrowing in."
Red Rain, Stine's first adult horror novel, is a solid read that has plenty of chills and thrills (the kind that films like Village of the Damned*, its sequel Children of the Damned and Who Can Kill a Child? [a.k.a. Island of the Damned] deliver).
Those who have read Stine's many children/YA horror novels should make no mistake: this is a 'for mature audiences' novel. It is not for children.
I enjoyed this plot-tight, genre-revering novel until its ending, which marred this otherwise worthwhile endeavor with a cheesy, Amateur Hour finish "twist" that cravenly apes the last-minute twists of lesser, often crappy movies and books.
Red Rain is worth reading, if you can overlook Stine's lapse in good judgment. These Amateur Hour end-twists may work in children's/YA books, but in adult fiction, not so much.
Check this out from the library, if you're interested in reading it.
[*Village of the Damned is based on John Wyndam's novel The Midwich Cuckoos.]