The vapor formation and the subsequent ignition of the plasma were studied at a Au wire cathode by recording simultaneously the evolution of the current (sample interval of 1 ms) and taking images of the working electrode with a high-speed camera (1000 fps, with background illumination). The electrodes were immersed in a 0.01 M KOH solution (about 50 °C, see experimental Section), and a voltage of 300 V was applied between the working electrode and the stainless steel counter electrode. The evolution of the current (blue, orange, and violet curve) during plasma ignition is shown in Fig. along with the measured voltage (black). Figures. 1b to g provide selected images of the system at different times along the current trace. The complete series of images (video) can be found in the Data Repository (see Data Availability Statement). For the following discussion, we set the time t 0 = 0 to the point where there is no evident contact between the electrode and the electrolyte anymore (see below).