Instant
Look
at
the
top
two
cards
of
target
opponent's
library.
Exile
one
of
them
face
down
and
put
the
other
on
the
bottom
of
that
library.
You
may
play
the
exiled
card
for
as
long
as
it
remains
exiled,
and
you
may
spend
mana
as
though
it
were
mana
of
any
color
to
cast
that
spell.
Flashback
