  The MSSM can arise as an orientifold of a pyramid-like quiver in the context
of intersecting D-branes. Here we consider quiver realizations of the MSSM
which can emerge at the bottom of a duality cascade. We classify all possible
minimal ways this can be done by allowing only one extra node. It turns out
that this requires extending the geometry of the pyramid to an octahedron. The
MSSM at the bottom of the cascade arises in one of two possible ways, with the
extra node disappearing either via Higgsing or confinement. Remarkably, the
quiver of the Higgsing scenario turns out to be nothing but the quiver version
of the left-right symmetric extension of the MSSM. In the minimal confining
scenario the duality cascade can proceed if and only if there is exactly one
up/down Higgs pair. Moreover, the symmetries of the octahedron naturally admit
an automorphism of the quiver which solves a version of the mu problem
precisely when there are an odd number of generations.
