 Björk first contacted Timbaland about a possible collaboration in December 2005.The first session took place in February 2006 in Studio 4 at Manhattan Center Studios in New York City, soon after Björk had visited Banda Aceh in February 2006 to view some of UNICEF's work with the children who were affected by the tsunami – in May 2005 Björk released the charity album "" to help UNICEF's work in the south east Asian region.Björk's experiences in Indonesia led to the track "Earth Intruders", originally a ten-minute song which Björk then subsequently edited for the album version.