  We solve the Wheeler DeWitt equation for the planar Reissner-Nordstr\"om-AdS
black hole in a minisuperspace approximation. We construct semiclassical
Wheeler DeWitt states from Gaussian wavepackets that are peaked on classical
black hole interior solutions. By using the metric component $g_{xx}$ as a
clock, these states are evolved through both the exterior and interior
horizons. Close to the singularity, we show that quantum fluctuations in the
wavepacket become important, and therefore the classicality of the
minisuperspace approximation breaks down. Towards the AdS boundary, the Wheeler
DeWitt states are used to recover the Lorentzian partition function of the dual
theory living on this boundary. This partition function is specified by an
energy and a charge. Finally, we show that the Wheeler DeWitt states know about
the black hole thermodynamics, recovering the grand canonical thermodynamic
potential after an appropriate averaging at the black hole horizon.
