  We find the superpotential governing the supersymmetric warped M-theory
solution with a transverse Stenzel space found by Cvetic, Gibbons, Lu and Pope
in hep-th/0012011, and use this superpotential to extract and solve the twelve
coupled equations underlying the first-order backreacted solution of a stack of
anti-M2 branes in this space. These anti-M2 branes were analyzed recently in a
probe approximation by Klebanov and Pufu, who conjectured that they should be
dual to a metastable vacuum of a supersymmetric 2+1 dimensional theory. We find
that the would-be supergravity dual to such a metastable vacuum must have an
infrared singularity and discuss whether this singularity is acceptable or not.
Given that a similar singularity appears when placing anti-D3 branes in the
Klebanov-Strassler solution, our work strengthens the possibility that
anti-branes in warped throats do not give rise to metastable vacua.
