Door is writing a letter. Of sorts.

( de Carabas: )
__

....yeah, right. Door snickers, trying to imagine him caring about that sort of thing, then writes on a small slip of paper.

( de Carabas: )

She shuts the piece of paper inside the compartment, slips a short, cryptic message about how to open it into the silver tube on the bird's leg, then opens the window. Opens the window, rather, reaching for the city-smell high above London instead of the salty air of Fandom Island. It's only a smaller door, after all; an opening is an opening, and it's certainly a big enough door for a pigeon to pass through.

//de Carabas// she says to it, cooing softly and stroking the top of its head from old habit, despite a mechanical bird presumably not caring about that sort of thing.

//Chimney!// it chirps in a tone half enthusiastic, half impatient, and flutters off into the air.

Door rather hopes that was a yes, as she closes the window again, then on a whim, opens it the regular way, letting in the fresh, cool island breeze.

[The door's closed, but the post's open!]