Lily (The Lady in the Lake)

Lily was the name adopted by the fourth and final incarnation of Lake, a Proto-Time Lord clone of River Song and the leader of a religious cult.

Biography
Lily was taken captive by Lake 3, who killed her in front of River Song, realising that she was a proto-Time Lord but not knowing where she came from or who she was. However, Lily didn’t regenerate, as she had used up all her allotted regenerations. Furious, River shot Lake dead, only to be shocked when he regenerated into Lily.

Realising what had to be done, River sent the newly regenerated Lake back in time so that River and Kevin could encounter her in the cave prior to her earlier incarnation killing her for the cycle to be complete. River then buried Lily's body. (AUDIO: The Lady in the Lake)