  I reconsider Hawking's analysis of the effects of gravitational collapse on
quantum fields, taking into account interactions between the fields. The
ultra-high energy vacuum fluctuations, which had been considered to be an
awkward peripheral feature of the analysis, are shown to play a key role. By
interactions, they can scatter particles to, or create pairs of particle at,
ultra-high energies. The energies rapidly become so great that quantum gravity
must play a dominant role. Thus the vicinities of black holes are essentially
quantum-gravitational regimes.
