Angular momentum of the secondary BH with respect to the center of mass of the entire system (all particles) for different runs (refer to Table 1). We have to bear in mind that, ultimately, we want to address the problem of the angular momentum of the system composed by the two BHs (in whichever external force’s field they may lie in). This is not what is shown in this plot. Because the primary BH is very massive and lies close to the center of the whole system, showing the correct quantity would only introduce the noise caused by the primary BH’s motion. Here, we opted to highlight the interplay of the secondary BH with the mass field.