  In the $\epsilon$-domain of QCD we have obtained exact analytical expressions
for the eigenvalue density of the Dirac operator at fixed $\theta \ne 0$ for
both one and two flavors. These results made it possible to explain how the
different contributions to the spectral density conspire to give a chiral
condensate at fixed $\theta$ that does not change sign when the quark mass (or
one of the quark masses for two flavors) crosses the imaginary axis, while the
chiral condensate at fixed topological charge does change sign. From QCD at
nonzero density we have learnt that the discontinuity of the chiral condensate
may move to a different location when the spectral density increases
exponentially with the volume with oscillations on the order of the inverse
volume. This is indeed what happens when the product of the quark masses
becomes negative, but the situation is more subtle in this case: the
contribution of the "quenched" part of the spectral density diverges in the
thermodynamic limit at nonzero $\theta$, but this divergence is canceled
exactly by the contribution from the zero modes. We conclude that the zero
modes are essential for the continuity of the chiral condensate and that their
contribution has to be perfectly balanced against the contribution from the
nonzero modes. Lattice simulations at nonzero $\theta$-angle can only be
trusted if this is indeed the case.
