Prologue: The Decision

Rose leaves the control room of the TARDIS after being told by the Doctor that she's not allowed to do yet another thing on board. It's driving her insane, honestly. The Doctor hasn't made it very clear what the boundaries are, and she's just so intent on pushing the nonexistent ones that it would have been better if he had. At least then she would know for definite when to stop.

She heads to the library, an idea forming in her head. She knows that he's had companions before- oh yes, that had been hammered right home- but now she's wondering whether or not they had the same problems as she has. Can't hurt to check.

She starts pulling out books at random. It doesn't matter, because the Doctor doesn't really tidy up in the library. For all he says he can't stand people leaving books lying around, he does just that an awful lot himself.

The History Of Raxicoricofallipatorius, by E. Blight.

Rose blinks. Maybe not. And chucks the book over her shoulder.

Hexakosioihexekontahexephobi a: An Irrational Fear?

She doesn't even bother to check who the book is by before throwing it down to her feet.

Twenty minutes later and Rose is no closer to finding what she's looking for. Defeated, she sits at one of the tables in the library, pushing several books off it and resting her elbows nonchalantly on the surface.

Then, she spots it.

A pad of lined paper, in front of her, just waiting to be opened and written in.

Rose pulls it towards her and snatches a pen off the floor, chewing it thoughtfully with no regard for where it's been before this.

After a moment, she titles the first page:

To The Doctor's Next Companions, Love Rose Tyler

And she begins to write.