The moisture content and vertical distribution in the extratropical UTLS is important for radiative properties in particular with a perspective to anticipated change of tropopause height and moisture content due to rising greenhouse gas concentrations. We present a Lagrangian perspective on various processes that control the extratropical UTLS moisture content including deep convection and warm-conveyor belts as well as cloud and mixing processes close to the local tropopause. The analysis combines various data sources on UTLS moisture including high-resolution ICON simulation and ERA5, but also observational data from aircraft and satellite.