Process tracing methods, which involve ways of using information within a single case to think carefully about questions of social-science theory, have become one of the leading qualitative methods in political science and related fields. Can mixed-method approach to process tracing work without destroying the qualitative logic of the method? This chapter argues that two distinct forms of process tracing, involving testing of existing causal theories and discovery of new theories, each have room for mixed-method strategies. We show that qualitative components can become steps within a testing-based process tracing argument, and offer guidelines for structuring such studies. We then offer a novel approach to combining machine-learning techniques like LASSO regression with discovery-based process tracing, illustrating the design with an application to the rise in visibility of U.S. far right broadcaster Alex Jones.