Looking for a title in which the protagonist is involved in a confrontation against an antagonist/opponent/evil forces, with a personal reason for being involved. But the protagonist doesn't know about it. He participates for some other, unimportant reason. It is only after a while that one learns what the protagonist has in common with the confrontation.

For example, the title "Slave B." The protagonist is unaware that he is the son of heroes, but participates, for the sake of earning freedom for himself and his sisters.