In an era of “philanthrocapitalism” and “dark money” (Jane Mayer, Dark Money: The Hidden History of the Billionaires behind the Rise of the Radical Right, 2016) in which billionaires appear to play an outsized role in global policy, this timely book explores their impact. Peter Hägel provides case studies of seven billionaires as transnational actors; importantly, he links agency with power and intention (pp. 42–45). Hägel has taken on a difficult analytic challenge examining the agency of actors who are not directly accessible. This raises methodological challenges that he addresses through a counterfactual analysis. Hägel largely succeeds in this effort and has produced an interesting analysis of the agency of billionaires, as well as the limits of their impact.