The device is a kind of combined camera and microscope that opens up whole new molecular worlds. Curretnly under construction in Hamburg, XFEL will be able to generate up to 27,000 X-ray flashes a second. The first components have been put together in a subterranean tunnel that’s seven kilometers long. Technicians and engineers are now testing components like magnets and the first detector for a "molecular cinema". The super-laser is due to enter service in 2017.