  We recently used Virasoro symmetry considerations to propose an exact formula
for a bulk proto-field $\phi$ in AdS$_3$. In this paper we study the propagator
$\langle \phi \phi \rangle$. We show that many techniques from the study of
conformal blocks can be generalized to compute it, including the semiclassical
monodromy method and both forms of the Zamolodchikov recursion relations. When
the results from recursion are expanded at large central charge, they match
gravitational perturbation theory for a free scalar field coupled to gravity in
our chosen gauge.
  We find that although the propagator is finite and well-defined at long
distances, its perturbative expansion in $G_N = \frac{3}{2c}$ exhibits UV/IR
mixing effects. If we nevertheless interpret $\langle \phi \phi \rangle$ as a
probe of bulk locality, then when $G_N m_\phi \ll 1$ locality breaks down at
the new short-distance scale $\sigma_* \sim \sqrt[4]{G_N R_{AdS}^3}$. For
$\phi$ with very large bulk mass, or at small central charge, bulk locality
fails at the AdS length scale. In all cases, locality `breakdown' manifests as
singularities or branch cuts at spacelike separation arising from
non-perturbative quantum gravitational effects.
