Abscission is the final event in cytokinesis, separating one daughter cell from the other. During cytokinesis, the contractile actomyosin ring constricts the plasma membrane at the division site and compacts the central spindle microtubules within the intracellular bridge (ICB). To allow fusion of the plasma membrane, these microtubules have to be disassembled – but how is this achieved? Using a combination of time-lapse microscopy and high-resolution 3D tomography, Rytis Prekeris and colleagues (p. 1411) now uncover the mechanisms that mediate abscission. The authors demonstrate that localised depolymerisation of the central spindle microtubules, which comprise most of the ICB, is not achieved by spastin-mediated severing, as originally thought, but by microtubule buckling. This buckling, and subsequent breaking, of the microtubules frees space in the ICB, so that FIP3- and VAMP8-containing recycling endosomes can be recruited and fuse with the plasma membrane in the next step of abscission. The increased rate of organelle fusion, in turn, enhances plasma membrane dynamics in the ICB and thereby leads to the formation of a ‘secondary ingression’ – a crucial step that drives the thinning of the ICB and, finally, scission. With these results, the researchers show that buckling of microtubules in the ICB is a key event in the process of abscission.