Story arcs
From the storyline tags ComicRack's scraper wrote into your files (AlternateSeries), grouped the way the tag groups them. An arc lists the issues you have; issues of an arc you're missing need Metron's arc lists, a later piece.
From the storyline tags ComicRack's scraper wrote into your files (AlternateSeries), grouped the way the tag groups them. An arc lists the issues you have; issues of an arc you're missing need Metron's arc lists, a later piece.