We are happy to announce the publication of a special issue “Biological fluid dynamics: emerging directions” in Philosophical Transactions of the Royal Society A. The special issue, which  presents contributions at the cutting edge of research biological fluid dynamics, crowns the epilogue of the (first?) Biological Fluid Dynamics Special Interest Group of the UK Fluids Network. It was co-edited by Marco, together with Dave Smith (U. Birmingham, UK), Smitha Maretvadakethope (Imperial College London, UK) and Laurence Wilson (U. York, UK). It has been an absolute privilege to work with Dave, Smitha and Laurence on this, and we were excellently supported by the editorial staff of Royal Society Publishing. I hope the issue will be of interest not only to the biofluids community but also to the many other scientific communities that intersect this vibrant interdisciplinary area. I wish you all a good read!