The proteins known as ABC exporters are highly dynamic molecular machines found in the cell membrane. They extrude a variety of substances from within the cell and as a result are involved in several key processes, including adaptive immunity and multidrug resistance. In this week’s issue, Robert Tampé, Arne Moeller and their colleagues report eight structural snapshots of an ABC reporter called TmrAB in action, presenting a picture of the various conformations adopted by the protein during substrate transport. The cover shows multiple protein complexes of TmrAB (blue and yellow) embedded in a cell membrane. The researchers used cryo-electron microscopy to capture the states in an imaging process that should be applicable to other transporters, many of which are intimately linked to human physiology and diseases.