Three Sentence Ficathon

"Grandfather, it is you!" the woman says, her smile tentative at first, then impossibly wide, and Yaz looks to the Doctor, expecting... she isn't sure what. A look of puzzlement, a laugh? But instead she spreads her arms wide and says, "Susan, it's me!", and Yaz thought she was used to all the Doctor's secrets and surprises, but what the hell is she supposed to do with this?