The plasma experiments in the Wendelstein 7-X fusion device at Max Planck Institute for Plasma Physics (IPP) in Greifswald, Germany, have been resumed after a 15-month conversion break. The extension has made the device fit for higher heating power and longer pulses. This now allows the optimised concept of Wendelstein 7-X to be tested. Wendelstein 7-X, the world’s largest fusion device of the stellarator type, is to investigate its suitability for a power plant.