Confocal microscopy image of human cells showing a rabies virus P3-protein (green) forming liquid-like droplets inside the nucleus (blue), localising to nucleoli, and binding to and bundling the cell’s structural framework called microtubules (red). Credit: Stephen Rawlinson, Monash University Key Points Viruses are masters of efficiency, able to take over our cells and control vital processes using only a handful of genes. For years, scientists have wondered how something so small could do so