The chairman of the Jockey Club hires Golgo 13 to kill a racehorse that is fraudulently labeled a thoroughbred. Shamed by his fraud he had tried to get his niece, Celia, to kill the animal. However as she had raised it and the horse is winning race after race she becomes fiercely protective. Sensing that she will try to put her own life on the line to protect the horse, he decides to tell her that he employed Golgo 13 to kill it, in the knowledge that the assassin would come after him. After failing to persuade Duke to stop, Celia tries to snipe Golgo before he can kill the horse, but his skill easily outmatches hers. Once the horse is dead and knowing that his job was revealed he goes after the chairman.
ダービー優勝の有力候補ギルフィ。ジョッキークラブの理事長グレイは、外国馬の血が混じる「彼女」に優勝を与えることはできないと、ゴルゴ13にギルフィの抹殺を依頼する。それを知った姪のシーリアは依頼を取り消そうとゴルゴの元に現れる。
