  In the background of a gravitational collapse, we compute the transition
amplitudes for the creation of particles for distant observers due to
higher-derivative interactions in addition to Hawking radiation. The amplitudes
grow exponentially with time and become of order 1 when the collapsing matter
is about a Planck length outside the horizon. As a result, the effective theory
breaks down at the scrambling time, invalidating its prediction of Hawking
radiation. Planckian physics comes into play to decide the fate of black-hole
evaporation.
