  We present a stability and convergence theory for the lossy Helmholtz
equation and its Galerkin discretization. The boundary conditions are of Robin
type. All estimates are explicit with respect to the real and imaginary part of
the complex wave number $\zeta\in\mathbb{C}$, $\operatorname{Re}\zeta\geq0$,
$\left\vert \zeta\right\vert \geq1$. For the extreme cases $\zeta
\in\operatorname*{i}\mathbb{R}$ and $\zeta\in\mathbb{R}_{\geq0}$, the estimates
coincide with the existing estimates in the literature and exhibit a seamless
transition between these cases in the right complex half plane.
