I'm trying to find a book I read in the late '70s (maybe the early '80s, but I don't think it was that late). Set in the present day, several people in a small town are having strange dreams that turn out to be messages from the future sent by two people coming back from to the past.
One, a man, is contacted by "Rodney" (I think that's the name, but I'm not sure). I don't remember what Rodney tells him, but it induces him to murder people in the manner of a serial killer.
The other, a woman, is contacted by "Starchild". This is where the bulk of the premise is explained: In the future, an environmental disaster has doomed life on Earth. Two people are sent back, separately, to do something to prevent the disaster. Time travel isn't instantaneous; it's more like getting in a capsule and moving at a finite speed through time. The traveler calling himself Rodney is a psychopath, has sabotaged Starchild's capsule so he'll die before arriving in the past, and they're both sending messages back via dreams (to what purpose, I don't recall).
There's also a psychiatrist that the woman is seeing in an attempt to make sense of these dreams she's having.
My memory tells me the book was named "Starchild". I've searched for every book I can find with that title (and there are a lot), but none of them match what I remember.