  In the following we undertake to derive quantum theory as a stochastic
low-energy and coarse-grained theory from a more primordial discrete and
basically geometric theory living on the Planck scale and which (as we argue)
possibly underlies also \tit{string theory}. We isolate the so-called
\tit{ideal elements} which represent at the same time the cornerstones of the
framework of ordinary quantum theory and show how and why they encode the
\tit{non-local} aspects, being ubiquituous in the quantum realm, in a, on the
surface, local way. We show that the quantum non-locality emerges in our
approach as a natural consequence of the underlying \tit{two-storey} nature of
space-time or the physical vacuum, that is, quantum theory turns out to be a
residual effect of the geometric depth structure of space-time on the Planck
scale. We indicate how the \tit{measurement problem} and the emergence of the
\tit{macroscopic sub-regime} can be understood in this framework.
