This first issue gives an overview of the status of the verification regime build-up and, as an overarching theme, it highlights the significant role of the Treaty in nuclear non-proliferation and disarmament. An interview with Sergei A. Ordzhonikidze, Secretary-General of the Conference on Disarmament, and a special feature article by Peter Marshall, an expert on seismology, focus on this theme. This issue also provides an update on the latest session of the Preparatory Commission, in addition to regular columns on verification science, the potential civil and scientific applications of the CTBT verification technologies and a column on the PTS staff, which introduces the PTS mission statement.