In the Land of Leadale, Vol. 3 (manga)

Cayna's new life had gotten off to a good start-she'd reached the royal capital of Felskeilo, gotten in contact with her three children, and taken on some commissions as a rookie adventurer. But after she learns a shocking truth about the land of Leadale from one of her fellow Skill Master's Guardian Tower that's been abandoned for these past two hundred years, it's hard for her to stay quite so upbeat...