  We define a three-dimensional quantum theory of gravity as the holographic
dual of the Liouville conformal field theory. The theory is consistent and
unitary by definition. The corresponding theory of gravity with negative
cosmological constant has peculiar properties. The quantum theory has no
normalisable AdS3 vacuum. The model contains primary black holes with zero
spin. All states can be interpreted as black holes dressed with boundary
gravitons. There is a unique universal interaction between these states
consistent with unitarity and the conformal symmetry of the model. This theory
of gravity, though conceptually isolated from other models of quantum gravity,
is worth scrutinising.
