2004 saw the release of Peccatum's third and final studio album, "Lost in Reverie", with an EP titled "The Moribund People" following the year after. On September 30, 2005, Emperor made a surprise return at "Scream" magazine's 15-year anniversary party at Rockefeller Music Hall in Oslo. The show was kept top secret, only known by a handful of people. The band played three songs. This was to announce the reuniting of the band for a few shows around Europe and America in 2006, namely at Wacken and Inferno Festival.