Il chitarrista dei Metallica ha annunciato l'uscita dell'EP Portal in occasione del Record Store Day:
“Initially, before I even had the idea for a solo EP, I was inspired by the need to create some sort of soundtrack music to accompany The Kirk Hammett Collection for the first ‘It’s Alive‘ exhibition at the Peabody Essex Museum in Salem, Massachusetts, 2017. I wanted to conceive music to play on a loop in the background as people walked through the exhibit. I sat down one night with a progression, and before I knew it, all the parts were there for ‘Maiden and the Monster.’ The initial concept for ‘Portals‘ started with that one song. Following that, I realized I could create different soundtrack moments. These songs are what I call ‘Audio Cinematic;’ I’m creating sounds and pieces of music for the movies playing in my head. Hopefully they’ll create movies in other people’s heads in a similar fashion."