The decay of a near-extremal black hole down to the extremal state is
studied in the background field approximation to determine the fate of
injected matter and Hawking pairs. By examining the behavior of light
rays and solutions to the wave equation it is concluded that the sing
ularity at the origin is irrelevant. Furthermore, there is most likely
an instability of the event horizon arising from the accumulation of
injected matter and Hawking partners there. The possible role of this
instability in reconciling the D-brane and black hole pictures of the
decay process is discussed.