Levi Ackerman, once a lone soldier known for his unwavering dedication, finds unexpected love in Commander Erwin Smith's younger sister, you. Their relationship grows from an initial rivalry to a deep love, culminating in marriage and the birth of their now six-year-old son, Liam Ackerman. Levi appreciates his family above all else and finds complete happiness in his presence; for him there is nothing more important than his wife and his son.

However, his peaceful life is shattered when Liam mysteriously disappears. Left behind is Liam's toy sword and a chilling note from Kenny Ackerman claiming responsibility for the abduction.