Fans have been receiving postcards from Biffy Clyro that includes a link to a mysterious site.
Having updated their social media pages with a blank cyan header and picture, Biffy Clyro seem to be hinting at their return.
The band took their teasing tactics to a new level by sending out postcards styled like a panatone paint chip, with the same colour as their social media headers and pictures.
Biffy Clyro's postcards also included the colour code for the cyan colour - 2197 C - as well as a link to a mysterious site which shows an image of a handwritten note that reads: "Dear God, Adjust my dreams for me. All I learned is Instant History."
The hashtag "#THISISTHESOUNDTHATWEMAKE" is also featured on the page linked from the postcard.
One fan theory suggest that 2197 is 13³ (cubed), which could hint that a potential release date for their new album - 13 March.
Although they haven't released a new album since 2016, Biffy Clyro haven't exactly been quiet - they released their Balance, Not Symmetry film score last year, and contributed a cover of Frightened Rabbit's "The Modern Leper" to their Tiny Changes - A Celebration of The Midnight Organ Fight album.