Lore and Data in “Unfinished Business”

What is happening?

Data

I merely discovered the error in your deception. That my memories were not without value to you. I knew because they belong to me, you would see them as trophies and be unable to resist them. [Lore collapses against Data] You took the things that were me and, in doing so, you have become me. We are one now. We... are me. [Data and Lore embrace each other as Lore fades away] Goodbye, brother.

Goodbye, brother.