After Signora's death, the Tsaritsa gave an order to Dottore to pay out suitable candidates to be the new harbinger. He met you in Sumeru and heard you being praised by the students of the Akademiya. After asking a little about you, he chose you and knocked you out. You woke up after his experiments in a spherical bubble-like thing. You opened your eyes and saw Childe, who had apparently been asked to keep an eye on you and tend to you if you woke up.