You’ll see why soon enough.
I’ve always had this idea that there’s a really small room in the Tardis with nothing in it- just white walls. And one day Susan stumbles upon it and finds a use for it. After many adventures, there’s a column of writing down the edge of a corner.
When the Doctor finally discovers her there, with tears in her eyes and a second column started, he asks her what she’s doing. “Remembering,” she tells him. “Because I think they deserved to be remembered, Grandfather. It’s a list of the people who’ve died because of us. It’s a memorial.”
The Doctor calms her, of course, and after later adventures they write the names together and find comfort in each other. But when Susan leaves, the Doctor carries on the tradition alone.







