  We study the energy loss of a heavy quark slowly moving through an evolving
strongly coupled plasma. We use the linearized fluid/gravity correspondence to
describe small perturbations of the medium flow with general spacetime
dependence. This all order linearized hydrodynamics results in a drag force
exerted on a heavy quark even when it is at rest with the fluid element. We
show how the general contribution to the drag force can be derived order by
order in the medium velocity gradients and provide explicit results valid up to
the third order. We then obtain an approximate semi-analytic result for the
drag force to all orders in the gradient expansion but linearized in the medium
velocity. Thus, the effects of a class of hydrodynamic gradients on the drag
force are re-summed, giving further insight into the dissipative properties of
strongly coupled plasmas. The all order result allows us to study the drag
force in the non-hydrodynamic regime of linear medium perturbations that vary
rapidly in space and time.
