A standing water wave of infinite depth and zero surface tension. This wave comes close to forming a 90 degree interior corner angle at the wave crest. However, if the wave amplitude is increased further, the crest does not sharpen to 90 degrees as predicted by Penney and Price. Instead, small scale oscillatory structures form near the crest tip, and a vertical jet of fluid pushes these structres upward, yielding wave profiles similar to those observed in wave tank experiments of G I Taylor. See PhysRevLett.107.184501 for details. (This movie is solution B in Figures 1-4). Note: the particles are passive tracers, added for visualization and color coded by pressure. (movie is 11.4 MB)