[4] The album is accompanied by a bilingual hardback book and audiobook, Eviga riket, which features new soundscapes and pieces of music written and performed by the band.

Upon moving their practice space to a different spot on the same site, the band uncovered long forgotten relics of the hospital, including old apparatus and medical journals.

The fake concept was accepted by journalists until the launch of the Eviga riket book, when literary critics picked up on the fallacies of the story.

Ahead of the book's release, Erik Jonsson of Västerbottens-Kuriren theorized that the persona of Holger Nilsson must be part or entirely fiction.

[8] The name is a play on Nils Holgersson, and other aspects of the fictional story are based on jokes within the band's personal lives.