This document summarizes a research paper on the first stage ("Explore") of Critical Systems Practice (CSP), a multimethodology approach for intervening in complex real-world problems. The Explore stage involves starting a multimethodological study of the problem situation. It is important to properly explore the problem upfront in order to identify opportunities for an effective, in-depth systems intervention and avoid approaches that could worsen the problem. The document provides background on CSP and critical systems thinking, and describes the latest version of the Explore stage, illustrating it with examples of applying it to study the UK health system's response to COVID-19 and creating a new business school.