  Approaches to quantum gravity often involve the disappearance of space and
time at the fundamental level. The metaphysical consequences of this
disappearance are profound, as is illustrated with David Lewis's analysis of
modality. As Lewis's possible worlds are unified by the spatiotemporal
relations among their parts, the non-fundamentality of spacetime---if borne
out---suggests a serious problem for his analysis: his pluriverse, for all its
ontological abundance, does not contain our world. Although the mere
existence---as opposed to the fundamentality---of spacetime must be recovered
from the fundamental structure in order to guarantee the empirical coherence of
the non-spatiotemporal fundamental theory, it does not suffice to salvage
Lewis's theory of modality from the charge of rendering our actual world
impossible.
