SOLVED. teen/tween book, two classmates sharing the same dream [s]

[Hillary]

I'm looking for a book I read in the early 1980s, but it was a battered paperback then. Two classmates who don't really know each other, I think one is a boy and one a girl, discover they are sharing the same scary dream when one sees the other in the dream. The dream has clues that they piece together to discover what it means. I remember that they find another boy who is dreaming the dream too, and together they need to do something. (view spoiler)[I think the three children were all together for an alien landing that they were too young to remember (hide spoiler)]

Paperback, I think a mostly black cover, title had "dream" "go into the dream" "into the dream" or something like that, but search for those leads to tons of books with "dream" in the title.

[Andria]

probably Into the Dream by William Sleator.

[Kris]

Into the Dream by William Sleator for Andria's suggestion.

[Hillary]

That's it! I read my way through everything Sleator had written, and never even thought of him for this one.