Machine Head may or may not be working on its followup to 2014's Bloodstone & Diamonds currently, though we'd venture to guess they are. Machine Head took to Instagram to post a few mystery pictures that indicate they're either in the studio or currently demoing new material.
The reason I'm guessing they're in the studio with Converge's Kurt Ballou is because the sticker below seems to be a callout to Ballou, who has the same sticker on his computer. Who knows if it was intentional or not, but hey – what if we're right?