This article applies the case of Tali Fahima, an Israeli woman who was convicted of aiding the enemy during wartime, in order to analyse how the ethno-national community is threatened by members it fails to control and fit into existing categories. The author argues that what makes an assumingly bright boundary so sensitive and problematic to cross is not its impenetrability but its actual vulnerability. The state tries to police uncertain citizens and if necessary to expunge them from the collective in order to imagine the boundaries as bright again. The author examines how Fahima used her privileged body to protect a Palestinian insurgent and the ways in which her body is invested with the meanings of national, ethnic and sexual boundaries and analyses how the Israeli security services, courts, media and public define proper citizenship and belonging.