  We study the dynamics of anti-M2 branes in a warped Stenzel solution with M2
charges dissolved in fluxes by taking into account their full backreaction on
the geometry. The resulting supergravity solution has a singular magnetic
four-form flux in the near-brane region. We examine the possible resolution of
this singularity via the polarization of anti-M2 branes into M5 branes, and
compute the corresponding polarization potential for branes smeared on the
finite-size four-sphere at the tip of the Stenzel space. We find that the
potential has no minimum. We then use the potential for smeared branes to
compute the one corresponding to a stack of localized anti-M2 branes, and use
this potential to compute the force between two anti-M2 branes at tip of the
Stenzel space. We find that this force, which is zero in the probe
approximation, is in fact repulsive. This surprising result points to a
tachyonic instability of anti-M2 branes in backgrounds with M2 brane charge
dissolved in flux.
