In this work, we obtain some general results on information retrieval
from the black hole interior, based on the recent progress on quantum
extremal surface formula and entanglement island. We study an AdS black
hole coupled to a bath with generic dynamics, and ask whether it is
possible to retrieve information about a small perturbation in the
interior from the bath system. We derive a state reconstruction formula
based on one norm. However, we show that a contradiction arises if we
apply this result to a special situation when the bath dynamics includes
a unitary operation that carries a particular measurement to a region A
and send the result to another region W. Physically, the contradiction
arises between transferability of classical information during the
measurement, and non-transferability of quantum information which
determines the entanglement island. We propose that the resolution of
the contradiction is to realize that the state reconstruction formula
does not apply to the special situation involving
interior-information-retrieving measurements. This implies that the
assumption of smooth replica AdS geometry with boundary condition set by
the flat space bath has to break down when the particular measurement
operator is applied to the bath. Using replica trick, we introduce an
explicitly construction of such operator, which we name as "miracle
operators". From this construction we see that the smooth replica
geometry assumption breaks down because we have to introduce extra
replica wormholes connecting with the "simulated blackholes" introduced
by the miracle operator. We study the implication of miracle operators
in understanding the firewall paradox.