  Transfer of quantum information from the interior of a black hole to its
atmosphere is described, in models based on effective field theory. This
description illustrates that such transfer need not be violent to the
semiclassical geometry or to infalling observers, and in particular can avoid
producing a singular horizon or "firewall." One can specifically quantify the
rate of information transfer, and show that a rate necessary to unitarize black
hole evaporation produces a relatively mild modification to the stress tensor
near the horizon. In an exterior description of the transfer, the new
interactions responsible for it are approximated by "effective sources" acting
on fields in the black hole atmosphere. If the necessary interactions couple to
general modes in the black hole atmosphere, one also finds a straightforward
mechanism for information transfer rates to increase when a black hole is
mined, avoiding paradoxical behavior. Correspondence limits are discussed, in
the presence of such new interactions, for both small black holes and large
ones; the near-horizon description of the latter is approximately that of
Rindler space.
