  Quantum gravity in an AdS spacetime is described by an SU(N) Yang-Mills
theory on a sphere, a bounded many-body system. We argue that in the high
temperature phase the theory is intrinsically non-perturbative in the large N
limit. At any nonzero value of the 't Hooft coupling $\lambda$, an
exponentially large (in N^2) number of free theory states of wide energy range
(of order N) mix under the interaction. As a result the planar perturbation
theory breaks down. We argue that an arrow of time emerges and the dual string
configuration should be interpreted as a stringy black hole.
