FllbB is crucial for assembly of the spirochetespecific periplasmic flagellar collar. Cryo ‐electron tomography of flagellar motors from wildtype (left) and ΔflbB (right) reveals the 3D collar structure, which is critical for flagellar orientation, cell morphology, motility, and stability of flagellar motors in Borrelia burgdorferi. For details, see the article by Moon et al. on pp. 33 6–348 of this issue.