HBO's harrowing miniseries Chernobyl just wrapped up its five-episode run on HBO this week, and adding to its palpable sense of dread is Icelandic composer Hildur Guðnadóttir's haunting, ambient score that has its own fascinating backstory. Her score was created from field recordings made inside the decommissioned Lithuanian power plant where the miniseries was filmed. "Right before they went there to shoot, I went there to record," Guðnadóttir told Score: The Podcast. "I went there with my score producer, Chris Watson, who records all the David Attenborough films and episodes. So he’s a master field recording engineer. We went in [the nuclear plant] in full hazmat suits and everything. We went there to record the power plant, and we worked the score from those recordings. Every single sound in the score is made from those power plant recordings.” Specifically, the ambient sounds. "I didn’t really want to play it as such, but I wanted to go there and experience what it’s like to be in a power plant." You can listen to the score below. and watch her talk about creating it on Score: The Podcast, below.

Hildur Guðnadóttir is also a cellist and choral arranger who has toured with Animal Collective and Sunn O))), worked with The Knife, Throbbing Gristle, Ben Frost, Nico Muhly, Múm and more. Her score work also includes Sicario: Day of the Soldado and she collaborated with the late Jóhann Jóhannsson on the score to Mary Magdalene.

You can watch Chernobyl on-demand or via streaming apps HBO GO and HBO NOW.