  Exact Kerr-Schild (KS) solutions for electromagnetic excitations of
black-holes, have the form of singular beams supported on twistor lines of the
KS geometry. These beams have a very strong back-reaction on the metric and
horizon and create a fluctuating KS geometry occupying an intermediate position
between the classical and quantum gravities. We consider the Kerr theorem,
which determines the twistor structure of the KS geometry and the corresponding
holographic prequantum space-time adapted to subsequent quantum treatment.
