The second Interzone release in the Not Two catalog, returning the trio to its founding core: Romanian pianist Mircea Tiberian with German bassist Horst Nonnenmacher and drummer Maurice de Martin. The title evokes the group's guiding metaphor — the 45th parallel as an imaginary boundary between East and West — and although issued after the earlier Interzone albums, its material was the first the group recorded. Stripped to the founding trio without guest soloists, it is the most distilled expression of Interzone's border-crossing piano-trio music.