Part 2 of 2. Should be subtitled "the benefits of saving your work."
When we left The Doctor last week, the Vashta Nerada were on a microscopic, flesh-eating rampage around the universe's biggest library. And Donna was saved into an information point.
This time we found Donna living a virtual reality life, created when she was saved into the library's computer. Something she only discovered when a veiled lady representing Miss Evangelista (saved as a data ghost and very intelligent), appeared in her virtual reality world All the people in the library were saved to the hard drive of the computer - the little girl, CAL.
We are left to speculate on the identity of Professor River Song.
1. She knows The Doctor's future (written down in the little book of spoilers).
2. He gave her a sonic screwdriver (which in the end, saved her life).
3. She knows his name.
So who is she?