Some of our sisters who shared our misery at Academy experimental camp have either stayed behind, or gone missing during our escape. It also stands to reason that like-minded souls have fallen on bad times elsewhere in this cruel world. Such people can be rescued and invited into our ranks ('Recruit' under Workshop's 'Recruitment' category; after the project is completed, she'll take 24 further hours to orient and recuperate). Fighting ranks, or even Brainers' ranks - the latter after further research. Or we can make them our slaves - like I said, it's a cruel world.