  We look for ways to destabilise the vacuum. We describe how dense matter
environments source a contribution to moduli potentials and analyse the
conditions required to initiate either decompactification or a local shift in
moduli vevs. We consider astrophysical objects such as neutron stars as well as
cosmological and black hole singularities. Regrettably neutron stars cannot
destabilise realistic Planck coupled moduli, which would require objects many
orders of magnitude denser. However gravitational collapse, either in
matter-dominated universes or in black hole formation, inevitably leads to a
destabilisation of the compact volume causing a super-inflationary expansion of
the extra dimensions.
