 "Endless Forms Most Beautiful", announced as the second single on April 17, was released with a lyric video on May 8.After releasing "Imaginaerum" in late 2011, the band began the Imaginaerum Tour in January 2012 with Anette Olzon as a vocalist and Troy Donockley as an unofficial member.On September 28, before a show in Denver, Olzon became ill and was replaced by Elize Ryd and Alissa White-Gluz (vocalists for Amaranthe and The Agonist, respectively).