Single-molecule imaging techniques have revealed the dynamic nature of ion channels and shown that channel activity is sometimes dependent on their mobility and mechanical forces in the lipid membrane. The cover image shows a recent high-resolution cryo-EM image of the two-pore structure of the core complex of the mitochondrial outer membrane protein translocase (TOM) from the filamentous fungus Neurospora crassa, together with a single-molecule false-color image illustrating the calcium flux through its two pores associated with conformational changes of this protein complex. The TOM core complex undergoes reversible transitions between active (high intensity pink dots), weakly active (medium intensity pink dots) and inactive (low intensity pink dots) channel states corresponding to the suspension of movement. For more information, see the article by Nussberger and colleagues (pp. 911–922) in this issue. Image provided by Shuo Wang.