This call invites empirically grounded contributions to an international edited volume on reprisals against individuals exposing systemic harm across health systems, science, academia, and governance, coordinated within the EU COST Action BEACON and published open access by Open Book Publishers under a diamond model with no fees. The project focuses on documented forms of retaliation such as administrative sanctions, legal harassment, professional exclusion, reputational attacks, and threats to safety, adopting a One Health perspective and strict evidentiary standards. Submissions are open to researchers, professionals, citizen scientists, journalists, and affected populations, with support for collaboration and access to COST funding instruments. Chapters will undergo transparent open peer review, with publication scheduled for late 2027, followed by a free online conference where authors will present their work to support dissemination and awareness.