This body of yours is a wonder.
Each new body is a wonder, but this one demands your attention in ways that might frighten you, except that you are not easily frightened. (You must never let anyone know you are frightened.) This body delights in itself; perhaps the hair is the wrong colour, but it stands up most expressively and the fact of it pulls your mouth into a grin. Learn its expressions, looking into the mirror while Rose sleeps in another room: here is what your eyebrows can do, your mouth, your chin, your eyes. Know the body is beautiful, not intellectually as you have known the strengths and weaknesses of your other selves, but viscerally; let the way you move be the declaration of intent.
Live with the consequences, as you always do. Watch Rose change because you have changed. She was beautiful too once, charged and filled with the whole of time and space, and you let yourself die to save her from burning up from the beauty. She doesn't remember it, and now what you were too fades in the face of what you are. Watch her smile mirror yours. Laugh with her and, with each smiling breath you take, fade a little. Let her wrap herself up in adventure, and allow yourself the knowledge that once, in another skin, you loved her without fear.
The older you are, the more human. Lifetimes ago you would not have allowed humans aboard your TARDIS. Find their cultural references coming out of your mouth; grin your spontaneous grin whenever they do something clever. Find new affections and charms in old things; this is not new, this relegating to mere memory all the things that were once of staggering consequence. Hug Sarah Jane and do not apologise. When you see the way she looks at you, with no surprise in her face for this new form, but some peculiar hungry affection, do not turn away; grin.
Never turn away.
If your body is beautiful, let it be. Let Sarah Jane look at you as though she has never seen you before, not you the form but you the function, every last bit of yourself new. When you take Rose to New New (New New New New New -- discover this too, some delight of your lips and tongue that makes you talk so rapidly you might one day collapse into breathlessness) York, do not be horrified that she kissed you. She never remembers kissing you, not in this form nor in the last. Do not remind her: know her limits and find your kisses elsewhere. Rose will worship you with all that she is, but you do not want worship.
You don't know what you want. Do not try to find it.
Instead, you must laugh because Rose laughs. You love her; of course you love her. Tell yourself this when you sit in the abyss of space orbiting a black hole, and she gives you a look that turns your hearts over in terror (never let her know you are frightened) and talks of mortgages and kisses the helmet of your spacesuit with all the tender worship she has. Do not tell her you love her; only tell yourself. Lie because you like it.
When you meet Reinette, feel no fear. There can be no lies around Madame de Pompadour, not when she can see into your mind. (She reminds you of -- but that was long ago; of no consequence. They are all dead now. Let them remain so.) Reinette understands you, form and function, as perhaps no other human ever has; allow her this. Know from the moment you meet her that you are her lonely angel, some guardian from a dream world on the other side of space and time; if you are Reinette's myth and Reinette's dream, you are safe. When you lie, lie to yourself as well: of course you mean to come back for her.
Tell yourself you never mean to leave any of them behind. Not Reinette, not Jack, not Sarah Jane. Not Rose.
Burn out a sun to say goodbye to her. Talk about nothing at all and let the body, which you fit into now without difficulty or question, do the rest for you. Grin with all the affection you have ever felt for Rose Tyler, even when she says I love you. You've known it for a long while and now that you are insulated in another reality you are safe from Rose Tyler's love. Tell yourself it's best: standing as an echoing shadow on Bad Wolf Bay, you open your mouth and vanish from her world forever. This is best; you owe it to Rose Tyler, just this once, not to lie.
Here is something that does not differ, whatever form you take: no matter how lonely you are, no matter how easily the humans see this you and fall into loving, you have forgotten how to travel by yourself, just you and your TARDIS and the universe. When you spend a frantic day with Donna Noble, ask her to come with you; how could you do otherwise? Know she is right. Sometimes you need someone to stop you, even if it is not Donna Noble, because Rose Tyler never did.
Meet Martha Jones.
When she recognises you, know. You came up to me and took your tie off, she says, and in that moment, know she is important. Her bedside manner is wonderful and she knows straight off exactly how alien you are. Take note of this; let the body do as it does, and wink at her, and grin, and watch as she goes, and know. Continue watching: she keeps her head, asks the right questions, marvels at the impossible beauty of the moon, thinks on her feet, shows amazing empathy, and instantly trusts you.
Discover something that you have long suspected of this body: in this form you love too easily and too well, and it frightens you.
Take her with you and know too, in an instant, how terrible a thing you are doing. She smiles at you wryly over the console and says I only go for humans; think Yes, me too, because with Gallifrey gone Earth is your best second. Martha is beautiful and she does not know your boundaries, and you don't know them either, because Rose knew the boundaries you used to have and insulated you both inside them. Martha tugs at you in new and unexpected ways, forcing you into peculiar growing pains. Find yourself saying Rose would know what to say, Rose would know what to do and when you see the hurt on Martha's face, pretend you don't understand. Lie because you like it, because testing the boundaries scares you, because you don't want to get hurt.
Expand the definition of one trip; you don't want to keep Martha Jones but you like her. Lose her at once; do everything you can to get her back. Get her back because you lied, because you were showing off, because you cannot decide what you want, because when those under your care are threatened, saving them is what you do. Make the mistake of forgetting that Martha Jones is Martha Jones, that she only needed rescuing as much as anyone else did in New New (New New New New New -- you said it before and somehow she knows) York; she is not Rose and she sits down in the alley and without any words she expects you to give something you have all but forgotten how to give.
You must never let anyone know you are frightened.
Sit down and explain Gallifrey to her -- not everything, not now, not when she is going to leave -- but enough, because Martha Jones is listening with not just her ears but with her single fragile beating heart, and no matter the body you inhabit, you know how to accept a gift.
(Tell yourself she cannot be right. You are alone, whatever the Face of Boe said. One human woman existing in your life for an eyeblink does not make you any less alone. You have learned this lesson well.)
Be grateful for an excuse to stay with her. You are learning that Martha Jones has an incredible capacity for saving people, and you are learning, too, to trust her. Trust her with the sonic screwdriver, trust her on her own, trust her to trust you. Trust her to come with you again, without caveats or excuses this time. Trust her to know when to speak and when to say silent, when your boundaries need pushing and when they need to be left alone. Know that she knows better than you ever can.
When you need her to do exactly what you say if any of you are to live, she keeps her head beautifully. Eyes squeezed tight shut, trying to keep hold of what you are, hearts beating with terror, burning and burning, feel her leave your side; cry out involuntary Martha, where are you? but she is still there, of course she is. Lose yourself so completely that you forget what you must never say; you have confessed your loneliness to Martha Jones and you can say it now, I'm scared -- I'm so scared -- and when she asks if you are ready, know you are past all lies. You are not ready and you tell her so and she shoulders it all; lose yourself and let Martha Jones be the doctor instead.
Don't look at her afterwards. She is still human, after all, full of glee for her own successes, although she stops it up at once and sets you first, again, as she always does, not because she worships you or even because she can instinctively see, but because she trusts you. You don't yet have the words to thank her; do the only thing you can, and give her a key to the TARDIS. The look on her face tells you she understands.
Take Martha, at length, to the Eye of Orion. She has not failed you yet. Sit her down amid the runes and mist, on the grass below the memorial; wrap a blanket around her shoulders and drink tea together from an old thermos. Tell her about the Time War, still not everything -- it can never be everything -- but more than you have ever told anyone else. Hold her hands and listen to her breathing and listen to her single beating heart and listen to her wonder at being trusted and your own for trusting until it fills the air between you so exquisitely that you know you will --
Spring to your feet and give her a grin and say Less angst, more fun!
Hold this last moment of knowing lodged like a beacon in your chest, a point of pure assurance precisely between the hearts Martha Jones has coaxed and bullied back to life. Know it immediately to be your solution when the Family of Blood finds you without warning and you come pelting around the corner and Martha ducks the blaster fire cool as you like as though dancing at Eurovision and avoiding death are all of a piece and she can do this forever. Ask You trust me, don't you? to hear her say Of course. Decide to become human because you've always wondered, because it's your safest option, because you trust Martha Jones with your life.
Leave her with a set of instructions. She must know she is wanted; she must know she is needed. Don't let me abandon you. You must not. You need her. You --
Lie, but only by omission.