The track "Room 24" features a massive coup for Volbeat with the guest appearance from King Diamond, the legendary front man of Danish metal pioneers Mercyful Fate, and one of Poulsen's musical idols. Volbeat reveals, "I'm a huge fan of Mercyful Fate and King Diamond. Having King on the record is a huge privilege. Normally, it's not something he does. He wrote his own lines, and it is half my lyrics and half his. It's a weird, scary story, and he's the perfect person for it."