A College student finds herself waking up in a world she once thought was fiction with only the clothes on her back, a permanently altered body, and with powers she logically cannot find an explanation for. Hint : She thinks it's a terrible deal. So it is up to her to find a balance between carving her own place in the world and meticulously planning the end of the apocalypse.

The Tarnished Warrior messes up while using Miquella's needle and promptly manages to evict herself from her own world. Desperate to not fade away in the space between worlds, she manages to grab hold of a summoning ritual. Being somewhat familiar with the process, even if it was different, she manages to summon herself into the Fourth Holy Grail War in Fuyuki as a Servant.