S3.E17

Lan Wangji tells Wei Wuxian that there is something he has not told him. Just then, Lan Sizhui and Wen Ning arrive, and, to Wei Wuxian's astonishment, Lan Sizhui recalls his identity as Wen Yuan. They have a tearful reunion, and Lan Wangji admits that this is what he had to tell him: he rescued Wen Yuan from the Burial Mounds, and took him to live as a member of the Gusu Lan Sect.