The faster, more powerful European XFEL free-electron laser has been inaugurated, producing ultrabright, trillion-photon x-ray flashes at a frequency 200× greater than the best preexisting free-electron lasers (FELs). The next-generation European instrument will allow scientists to map the atomic relief of viruses, decipher the molecular composition of cells, create 3D images of the nanoworld, and film chemical reactions. Eleven countries helped build the XFEL, and the French National Center for Scientific Research (CNRS) and Alternative Energies and Atomic Energy Commission (CEA) both played a leading role in the design and construction of the superconducting electron accelerator at the heart of this new international research facility. Since the 1970s, particle accelerators have been used to produce x-rays through synchrotron radiation. This technology is used for structural analysis of materials. FELs emit ultrabright, ultrashort flashes of almost perfectly coherent light, opening up new horizons for scientific investigation. The European XFEL uses a superconducting electron accelerator to generate 27,000 ultrabright x-ray flashes per second, a frequency 200× greater than its best FEL predecessors. With a length of 3.4 km, it is also the longest laser in its class. The European XFEL electron accelerator is a pioneer in the world of light sources as it is the only one to harness superconductivity. It was built by a consortium of European institutes, primarily based in France, Germany, Italy, Poland, Russia, Spain and Switzerland. European XFEL emitted its first beam in May 2017 and can now produce light with enough intensity to elucidate structures on nanometric or even atomic scales in a single pulse. Both the duration, on the order of a femtosecond, and the coherence of the light flashes will allow scientists to study the dynamics of biological structures, nano-objects and chemical reactions in real time. In addition, the laser's brilliance will enable induction and observation of excited states of matter such as those existing at the core of planets.