This article aims to illustrate radicalization towards jihadist terrorism as a non-sequential process. It focuses on both continued as well as unsuccessful trajectories of involvement, by studying how jihadists deal with social stimuli from their environment. The material objects of investigation were 28 voluminous police dossiers from the Netherlands; these yielding rich information on 209 subjects. In addition, 28 semi-structured interviews with police investigators, public prosecutors, and defense lawyers were conducted. By studying the factors that enhance, discourage, and sustain possible affiliation with a terrorist network, this investigation found two transformation processes. The first process shows how intended encouragements to internalize the radical ideology can be carried too far, having a counterproductive effect. The second process shows how seemingly discouraging factors are perceived as positive and therefore encourage further jihadist involvement. All subjects studied appear to have been confronted with mechanisms from transformation processes, indicating that even the involvement of experienced subjects is unstable and can fluctuate over time.