  For a finite group $G$, the so-called $G$-Mackey functors form an abelian
category $M(G)$ that has many applications in the study of $G$-equivariant
stable homotopy. One would expect that the derived category $D(M(G))$ would be
similarly important as the "homological" counterpart of the $G$-equivariant
stable homotopy category. It turns out that this is not so -- $D(M(G))$ is
pathological in many respects. We propose and study a replacement for
$D(M(G))$, a certain triangulated category $DM(G)$ of "derived Mackey functors"
that contains $M(G)$ but is different from $D(M(G))$. We show that standard
features of the $G$-equivariant stable homotopy category such as the fixed
points functors of two types have exact analogs for the category $DM(G)$.
