Mystic Story girl group Billlie has dropped a release schedule for their 5th mini album, 'appendix: Of All We Have Lost', the group's first comeback as 7-members in a year and 7 months. 

The upcoming mini album will serve as an "appendix" to Billlie's grand story line, as the title suggests. Official teasers begin on October 4 at midnight KST with a series of 'Fragments of Memory' teasers, followed by a succession of random track drops, "Trampoline" version teasers, "Memory Candy" version teasers, and more. 

Billlie's pre-release single "Trampoline" and its accompanying MV will be released laster this month on October 11 at 1 PM KST. Afterward, the group's full comeback with 'appendix: Of All We Have Lost' is slated for October 16 at 6 PM KST. 

Stay tuned for what's in store for the girls of Billlie in 'appendix: Of All We Have Lost'. 

SEE ALSO: Billlie to make a comeback next month