In the first episode of this series on mechanics, we introduced "mechanical quantities" or "mass-carrying quantities", mixing the dimensions of mass M, length L, and time T. In the following episodes we saw that these quantities can be understood by the effects they have when considered in pairs. Pairs of mechanical quantities lead to kinematic power laws. These power laws provide relationships between space and time, which seemingly extend indefinitely to arbitrarily small or large scales. In practice, any power law only extends over a finite range, beyond which other mechanical factors start to play a role, leading to crossovers toward different power laws. In this episode, we discuss how these transitions can be understood by considering three mechanical quantities. We show that the combination of three mechanical quantities lead to a special space-time point, an "event". These events provide turning points between different regimes, where the impelling or impeding factors are changing. Moreover, these events provide a way to define truly objective units, regardless of the perspective, to replace meters, seconds, and any other subjective combinations of these arbitrary standards. These objective units are not set by any standard, but by the phenomenon itself. We give four examples, based on the physics of detonations, droplets, waves, and turbulence.