Monolayer transition steel dichalcogenides are famend for internet hosting excitons, electron–gap pairs certain collectively by Coulombic attraction. Being analogues of atoms, they characteristic sharp traces in optical spectra1. Excitons can propagate within the monolayer airplane. Usually, they diffuse out of the spot the place they’ve been generated, propagating by fractions of micrometres throughout their lifetime2. Writing in Nature Nanotechnology3, Andrés Granados del Águila and associates now report on the experimental realization of a really totally different exciton propagation situation in monolayer MoS2: a fluid-like stream of excitons by a number of tens of micrometres at a pace of about 2 × 107 m s–1.