At the Diclonius Research Institute, Silpelit Number 3 has her vectors tested by having iron balls of increasing speed fired at her until a disgusted Kurama suspends the experiment, ending up chastised for it by his colleague Kakuzawa. Kakuzawa comes to the conclusion that Number 3's power will not grow any stronger. Her feeding time then follows suit, but when the attendant tosses food in her direction, she only sits there and ignores it.
In the nearby control floor, Kurama and Kakuzawa realize that Number 3 may have been holding back during her tests to make them underestimate her power. In her holding area, the technician feeding her and the guard accompanying him try to ward off the approaching Number 3, who can easily deflect his bullets and declares her desire for revenge upon her cruel mistreatment. In a motion, she beheads the guard and smashes his head into the technician's face.
When a silence emerges from that same floor and sensors show the holding area for Number 3 to be unlocked during her feeding time, Kurama calls an alert and rushes out, only to see her next to a dead body. She brushes her vectors across his temple, saying that she wished to meet the man behind the glass partition and express her gratitude to him. Whatever her intent, Kakuzawa shoots her from behind in the back of the head, killing her instantly. Almost cackling over his first kill by shooting, he recounts that Kurama is the only man on record to be touched by a Diclonius' vectors and live.
Kurama is forced to wonder if the late Number 3 sensed his sympathy for her plight, and prepares to help the wounded and the dead until a phone call reveals that his pregnant wife is in the hospital under emergency care. Attempting to comfort Hiromi after her miscarriage, he promises that, now that they know she can get pregnant, they will try again. In the narrative, he states that, six months after this, she became pregnant with Mariko.
- Much like Mary's little lamb, Nyu must have followed Mayu to school, as she is on this chapter's cover wearing a gym uniform complete with bloomers and a name tag.
- The title 'The Annunciation' may be a reference to the Biblical visit by the Archangel Gabriel to Mary, telling her that she would bear the child the angels directed her to name Yeshua or Jesus. In the case of this story, Number 3 seems to have unsettled Kurama's conscience and then caused him to sire Mariko. It is unknown if such a reference was the mangaka's intent.