This stunning view of the distant galaxy-cluster Abell S1063 was taken by the NASA/ESA Hubble Space Telescope as part of the Frontier Field programme. The cluster itself is seen as it was four-billion years ago – the time it took light to reach us. But the main goal of this observation is to explore a time even earlier than this, where no telescope has looked before. The huge mass of the cluster distorts and magnifies the light from galaxies that lie behind it due to gravitational lensing. This allows Hubble to see galaxies that would otherwise be too faint to observe and makes it possible to study the very first generation of galaxies in the universe. Three other clusters have already been observed as part of the Frontier Fields programme and two more will be observed over the next few years, giving astronomers a remarkable picture of how they work and what lies both within and beyond them.