The development of vacuum-compatible liquid sampling sources has enabled the use of ionizing radiation sources (XUV and X-rays) to study reaction dynamics in solution. This development is constantly evolving with improvements in light sources, such as the relative democratization of laser sources based on high-order harmonic generation, and improvements in liquid targets with the recent development of stable flat liquid jets with sub-micrometer thicknesses. The transvers nature of reaction dynamics in water across different scientific communities means that the spectroscopic tools available are extremely varied. These include time-resolved photoemission spectroscopy (femtosecond and even attosecond), highly nonlinear optics via liquid-phase HHG, chiral linear probe development (circular X-ray dichroism, PECD), RIXS, coincidence measurement (e-,e-), etc. This workshop will bring together users of these different tools. It will also provide an opportunity to compare and improve theoretical aspects of molecular dynamics in the liquid phase, thanks to the participation, we hope, of European experts in the field.