  Motivated by the lessons of black hole complementarity, we develop a causal
patch description of eternal inflation. We argue that an observer cannot
ascribe a semiclassical geometry to regions outside his horizon, because the
large-scale metric is governed by the fluctuations of quantum fields. In order
to identify what is within the horizon, it is necessary to understand the late
time asymptotics. Any given worldline will eventually exit from eternal
inflation into a terminal vacuum. If the cosmological constant is negative, the
universe crunches. If it is zero, then we find that the observer's fate depends
on the mechanism of eternal inflation. Worldlines emerging from an eternal
inflation phase driven by thermal fluctuations end in a singularity. By
contrast, if eternal inflation ends by bubble nucleation, the observer can
emerge into an asymptotic, locally flat region. As evidence that bubble
collisions preserve this property, we present an exact solution describing the
collision of two bubbles.
