Since the so-called 2015 Migration Crisis, great attention has been devoted to borders, activism and solidarity. While a part of the literature focuses on the political and/or humanitarian aspects of solidarity, this article suggests reading acts of solidarity through ethics. Looking at the Roya Valley, at the Italo–French border, I suggest that many local initiatives to assist and help migrants in transit were driven mostly by a sense of duty, rather than charity or political motives. The emergence of three specific circumstances–face-to-face encounters, conditions of emergency and a sense of duty–made locals offer solidarity because of a sense of responsibility. Faced with a choice between protecting themselves from legal charges or protecting human lives–those of migrants crossing along their route–or protecting themselves from legal charges, many border-people chose the first option. I, therefore, suggest that solidarity should be read through the prism of ethics. Building upon Levinas’ and Derrida’s ethics, I illustrate why face-to-face encounters make a difference and why response-ability requires impossible decisions. © 2021 Association for Borderlands Studies.