Peter Dickinson has a name for himself in the mystery genre as well as SF.
I've only read his "Changes" trilogy, a good juvenile series where almost
everyone in England develops a sudden loathing of machines.  Note that you
should read them in the reverse order that they were published, that's the
way the internal chronology works.

[J] == The book is for juveniles (however you define them)
[O] == Omnibus.  Includes other books

/John

arpa: JWenn.ESAE@Xerox.com

thewaysomepeoplefindfaultyoudthinktherewasareward-ly
----------------------------------------------------------------
Dickinson, Peter [Malcolm] [Zambia, U.K., 12/16/1927- ]
    The Changes Trilogy [1975] [O] [J] [aka "The Changes"]
        The Devil's Children [1970, 1986]
        Heartsease [1969, 1986]
        The Weathermonger [1968]
    Emma Tupper's Diary [1971] [J]
    The Dancing Bear [1972] [J]
    The Green Gene [1973]
    The Gift [1973] [J]
    The Poison Oracle [1974]
    King & Joker [1976]
    The Blue Hawk [1976] [J]
    Annerton Pit [1977] [J]
    Tulku [1979] [J]
    The Flight of Dragons [1979]
    Healer [1983] [J]
    A Box of Nothing [1985] [J]
    Eva [1988]
    Merlin Dreams [1988] [J]