So this was pretty much started by my interest in BDSM relationships and the dynamics in them- a theme which I hope to explore in further fics because it really interests me and there's so many possibilities with this pair. Then I reached the end and I think it ended up being about not only the physical ties Missy wants to play with but the emotional ties between the two and their ties to other people and even their ties to their old identities. So- enjoy I hope?
Okay so I finished writing this back in March and that bit with River in relation to the bit we saw in the trailer is too close it's freaking me out a little.

"I want you to tie me up." Her words are soft but hold a sharpness behind them that is just her. Her hand trails down his chest, nails tracing over the skin. She breathes against his neck, sending a soft tingling down his spine.

Until he processes the words that came before.

"Wait- what?" The Doctor sits up, the Mistress still straddling him. She maintains balance by wrapping her arms around his neck and pulling him close enough that he can see all the shades of blue in her eyes.

He can feel the silky touch of her stockings against his sides. He can feel the swell of her breasts, still clad in black lace, against his chest. He can feel his own hardness trapped between them.

Yet he ignores all of it.

Gently the Mistress rests her forehead against his and looks him directly in the eyes.

"I said I want you to tie me up." Her breath mingles with his as she speaks, mixing with his in the air between them. She shifts closer to him, pressing the full length of her corseted body against his bare skin. He can feel the thrumming of her twin hearts against his chest and is sure that she can feel his equally so.

"What do you mean?" Asks the Doctor, voice hoarse in the silence of the room. His eyebrows furrow, "I thought you made it clear that you wanted to be in charge? And I think I've certainly made it obvious that I don't want any part of controlling anyone Missy. I know you insist that I do but-" The Mistress rolls her eyes, pulling back from him with her arms still looped around his neck.

"It's not about me giving up dominance." She scoffs. The Mistress stops at that, waiting for the Doctor to figure it out. He rests his hands at her hips, softly running his thumbs over the smooth planes of her corset.

"Then why do you want me to tie you up?" He asks softly, frowning.

"How can you be in charge and me not be in charge?" The Doctor questions further, "If someone's doing the tying up they're taking charge. I don't want to control anyone Missy, let alone you." He starts gesturing erratically with his hands as he speaks, finishing with a horrified look at his bed partner.

The Mistress stares at him, unamused.

"You really don't understand this, do you?" She asks, one eyebrow raising. The Doctor sighs, hand rubbing at his temple.

"No." Is his simple response.

The Mistress smirks, eyes narrowing slightly.

"Well. I'll just have to explain it then, my dear Doctor." She says in a way which usually warrants either him being tied up or her trying to kill someone again. The Time Lady climbs off of him, patting his penis with an indulgent smile.

"We'll get to you soon." She promises. The Doctor rolls his eyes at his best enemy/ worst friend/ lover's antics despite feeling himself harden a little again at her touch.

"So." Missy begins, pacing, "In the bedroom we tend to fall into the roles of submissive and dominant- I being the dominant and you being the submissive." The Time Lord nods in agreement.

"Not much of a surprise when you called yourself the Master, is it?" He quips. Missy ignores him.

" So usually dominant behaviour is things like taking control and commanding and by contrast submissive behaviour is about obeying and being controlled." She says, "Of course there's the safe word, trust and all the health and safety regulations but that's the idea behind it really when you get down to it." Missy tags on the end before the Doctor can interrupt. He nods again, eyebrows descending once more as he tries to grasp where the Mistress means to go with everything.

"So why can't a dominant command a submissive to tie them up or do things a dominant stereotypically does? It's an order like any other, isn't it?" The Doctor opens his mouth to argue before bringing his palm over his mouth.

"Oh. I see." He says, "And this- wanting to be tied up- is just because you want to try it or you want to see how far you can take it or I can take it or-" The Doctor stops and frowns, looking directly into her eyes.

"It isn't- you don't want to push me into a more… violent approach to life. Do you?" He questions, uncertainly.

Again Missy snorts.

"You think I could do that? The whole fun of our game is that we're at opposite ends and neither will give in. You're too fixated on being a good man for that to happen anyway." She grumbles. Her face brightens as she steps back towards the bed.

"But. You did once say that if we travelled together I'd be clapped in irons and I know we aren't travelling together but that did excite me just a tinsy bit." She brings her thumb and forefinger together to indicate the amount, squinting at it. The Doctor looks at her unimpressed.

"Missy. No." He says bluntly.

The Mistress rolls her eyes.

"Alright, alright! I was only teasing… Spoilsport ." She responds, settling herself on the bed again, "Anyway- what do you think?" She asks finally.

The Doctor is silent for a few moments.

"You would be in control the whole time?" He asks tentatively. Missy nods.

"Yes. I will be in charge." She clarifies. The Time Lord nods, still thinking it over. Missy privately thinks he looks a little silly and quite adorable nodding to himself, completely naked, on her bed.

The Doctor nods decisively.

"Then yes. I don't know very much but I think I know enough for just trying it." The Mistress grins, leaning over to sling her arms around his neck and kiss his nose.

"Thank you." She says, infusing the words with her gratitude and appreciation.

"Now. Rules. First; you must always call me Mistress. Second; if you aren't sure about whether you can do something then don't. I don't want to lose a hand I can't replace. Third; if you feel uncomfortable use the safeword and we stop. I mean you'll have to untie me but we stop immediately. Fourth; if I use the safeword we stop and you untie me. The safeword is fish food." Missy summarises. The Doctor looks at the Mistress puzzledly.

"Fish food?" He asks.

"Fish food." Missy replies.

The Doctor shrugs.

"Works for me." He says. The Mistress smiles nastily.

"Good. I'm going to leave the room and come back. While I am out straighten out the bed sheets. When I return I want to find you sitting on the edge of the bed and ready for me." Missy says as she stands, already planning in her mind what kind of things her Doctor might and might not be comfortable with doing.

"Yes Mistress." He replies. The Mistress smiles, pecking his lips.

"Good boy." She brushes a thumb over his cheek and leaves the room, enjoying the feeling of the Doctor's gaze travelling down from her still damp hair to the ends of her stockinged feet. She closes the door behind her and goes to fetch some treated ropes, lubrication, condoms, a blindfold, a ball gag and lotion.

As she fishes the objects out of her fun room she considers the probability of using each- it should at least give the Doctor some time to get ready. She knows they will use the condoms and lube- they always do. Missy is fairly certain they'll use- or rather the Doctor will use- the ropes and if they use them there will still be enough soreness to require some lotion afterwards no matter how much the ropes have been softened. She thinks she might be able to convince him to blindfold her but is sure he won't be able to take her speech from her straight off given his nervousness. The gag is more of a gamble- an exciting possibility nonetheless.

She begins to walk back to the room, sure that ample time has passed for her dear Doctor to be all hot and bothered and that too little time has passed for him to have become bored and have finished himself without her help. Missy thinks she might only ask him to tie her hands and legs this time- just to ease him in. It's simple enough to do even without any experience either and the Time Lady knows from experience that if push comes to shove the Doctor is quite capable of restraining people.

"Mistress." The Doctor pants as she enters the room, hand still wrapped around his cock.

"Not intruding on anything am I?" Missy asks sardonically, heading straight for the bed. The Doctor stands up immediately, dropping his hand.

"No Mistress." He says instantly. The Mistress smirks, popping her bag on the side of the bed opposite to him.

"Good." She says cheerfully, "Because I need you remove my clothes for me. I've had quite a strenuous day and don't feel like doing these last few bits myself." Missy flops into a wooden chair as she speaks. She lifts one foot into the air, toe pointed as her hands clasp the seat to balance herself. The Doctor steps forwards.

"Get a move on. I want to be out of these as soon as possible." She drawls.

The Time Lord does as she says.

"Yes Mistress." He murmurs, low in his throat. He catches her foot and runs his hand along the inside of her leg. He caresses the softness of her thigh as he searches for the clip attaching the back of her stockings to her suspender belt. It pings back slightly when released but he is careful not to let it hit her. He dips his thumb briefly between her thighs, enjoying the way she leans back into the chair, foot settling gently against his shoulder as he reaches for the clasp at the front.

He undoes that one too, running his hands over her skin as he rolls the first stocking off. The second is just as simple to remove but the distraction of their position has both of them wondering whether they should just say to hell with the games for today and just fuck.

They look deeply into each other's eyes, breathing steady, trying to judge the other's tolerance for the teasing.

"We don't have all day." Missy says firmly, staring at the Doctor, "Hurry up." And he obliges, wrapping his arms around her waist and supporting more of her weight on his shoulders as he skillfully undoes the knot at the back of her corset. He pulls deftly at each loop until it is loose enough to unclasp at the front. The Doctor slips the underbust corset from beneath her and lets her drop back onto the chair.

Her bra and suspender belt unclip just as easily, giving the Time Lord the opportunity to trail his hands down her arms. He kisses the back of her hand and Missy smiles fondly.

"You forgot something." She says relaxedly, folding her arms behind her head. The Doctor shakes his head, kneeling down.

"No. I haven't forgot Mistress." Says the Time Lord, his eyes bright.

He brings his head between her legs, still settled one over each of his shoulders. The smell of her arousal is even stronger at its source and it takes a lot of restraint for him to not just take her there.

Carefully he takes the fabric of her underwear in his teeth and gently tugs it down her thighs. He pulls the damp fabric down past her knees, past her calves, to her ankles and off. He takes the flimsy lace from his teeth and places it with the rest of her lingerie. Her feet drop gently to the floor.

He stands again and Missy just watches him for a while, caught on the tension between them.

She smiles.

"Come. Rest your head against your Mistress' chest for a while." She says, opening her arms.

He does.

Her hearts are beating fast. He can hear them beneath his head through her soft skin.

They stay there for a while in the quiet.

"Now," says Missy, shifting to sit up better, "Stand up and sit on the same side of the bed as my bag." The Doctor obeys her command and stands, sitting down again next to the bag. He watches her as she stands too.

The Mistress walks softly past him. She brushes her fingers over his knee as she passes, moving her hand up his thigh as she sits down. Her chin come to rest over his left shoulder and she wraps her arms around him, feeling the four beat rhythm reverberating in his chest speed up.

"Now." She whispers, lips to his ear. Missy gasps, a little hitch which turns the Doctor's own breath ragged. The Time Lady smirks.

"Now." She whispers again, "Pick up the bag." Her hands slide down to his hips, coming tantalisingly close to his dick. The breath on his neck does little to help his self control.

"Yes Mistress." He croaks.

Slowly the Time Lord bends down, catching the handles of the flimsy bag with one hand. He holds it in his lap. Missy waits, just breathing oh so close to him. He can feel the rise and fall of her chest against his back, pebbled nipples grazing against his skin.

"Open it." She commands. He follows, eyes fixed on her lips as she peeks over his shoulder.

"Tell me what is inside it." She says, voice low in his ear. He wastes no time in cataloguing the contents of the bag.

"There's a few bundles of rope, a bottle of lube, condoms, a blindfold, some lotion and a ball gag." He pronounces each word clearly, quieting a little when it comes to the gag, clearly worried about using it.

Missy walks a hand up his stomach, up his chest and rests it loosely against his throat. He swallows.

"Mistress." He adds on.

The Time Lady smiles and removes the hand, taking his cock in it instead. He gasps.

"Good." She says lightly, slowly stroking his dick up and down. The Doctor groans, resting his head against Missy's.

"Those ropes." The Mistress whispers, hand still moving, "Take them out of the bag." He is quick to obey, hoping it will lend speed to her hand.

She still moves achingly slow.

"In a moment I will take away my hand. You will take both and tie them behind my back." Her lips are soft against his neck.

"Mistress." The Doctor moans, neither of them sure whether it is from the pleasure, or in protest.

Missy removes her hand, turning sharply so her back is to him. Her hands lay limp against the bedsheets.

Her chest heaves and she hangs her head as she feels his hands gently take her wrists. A breath rips through her as he tenderly wraps her wrists in rope, palm to palm. His fingers are warm against her skin.

Missy closes her eyes.

She sits a little straighter as he pulls the rope tighter. The fibres bite just a little but it's just enough to excite.

The Doctor's palm parts her hair and he kisses softly at the side of her neck.

"You're beautiful, Mistress." He whispers. Missy smiles feeling the heat of their childhood return to her cheeks.

The Mistress laughs, leaning back against him. The Doctor wonders if anyone could hate her having seen her as she is in his arms. His hands rest at her hips and he smiles too.

"Of course I am." She says simply. They wait again, enjoying the intimacy of mere contact. Missy can't hide the grin or the red bloom on her face. Her hearts beat fast and she chuckles again.

"The next ropes go around the thigh and calf of each leg." Says the Time Lady. The Doctor removes the last of the ropes from the bag and they turn to face each other.

The Time Lord shuffles closer, between Missy's open thighs. She lifts a leg slightly and the Doctor takes the folded limb in his own hands, binding it closed. The Mistress breathes steadily as he ties the second leg too.

His thumbs rest against the inside of her thighs, rubbing gentle circles.

"What now Mistress?" He says softly, against the backdrop of her sighs. His eyes are caught on the parting between her lips and the blue in her heavy lidded eyes.

The Doctor leans inwards, thumbs pressing into the dips where the Time Lady's legs join the rest of her body. The Mistress leans in too, touching their foreheads together as she bites her lip. Her eyes fix on his.

"The blindfold." She says.

Without looking he reaches behind him and fishes the small piece of fabric from the bag. His eyes observe her intently until they part.

He watches her for a few seconds longer, the two of them just breathing.

She does not flinch as he leans forwards again. Her eyes flutter closed as he takes her jaw in his fingers, pulling her towards him. She wets her lower lip.

Softly he places the blindfold over her eyes.

Although she can't see him Missy can feel the presence of the Doctor's chest only inches from her face and the shake of his hands as they tie the knot behind her head.

The ball gag will have to wait for some other time.

Those hands lay against either cheek.

"And now Mistress?" He asks quietly.

"Kiss me Theta." She says equally as gently.

The touch of his lips thrills despite her expectancy without the guidance of her sight.

His breath is sweet in a way only he could be. Tenderly he holds her face, lips pressed to hers.

The Mistress leans into him, parting her own lips as he pulls away.

Without needing any orders he kisses her again, arms encircling her as they both fall backwards, him between her thighs.

In the dark it feels like she falls forever with him. Time stretches on as their tongues meet again and again. Neither of them truly notice when they land despite the impact of the bed and the weight of the Doctor pressing the Mistress down.

They breathe heavily when they part, Missy shuddering. She can feel the heat in her cheeks echoed throughout her, crushing logical thought.

"Fuck." She mutters as the Doctor kisses and his teeth scrape the skin of her neck. She arches upwards as he nips at her collarbone, breath ripped from her.

The Doctor's breathing is harsh too as he labours his affections upon her.

A hand slips between her legs and she gasps out her shock, eyes flying open beneath the blindfold. Gently he presses a finger inside, lips still moving down her body.

She moans, thrusting her hips up to meet his hand.

"Doctor…" She gasps louder as he adds another finger, "Doctor…" The Mistress bites her lip as they move together. He kisses down her stomach and she pulls at the restraints.

His hand moves aside, painting her own wetness against her skin. She shivers. Both hands grip at the joins between her legs and her hips.

The Doctor dips his tongue between her folds. Missy blows out a breath, dropping her head back further. Everything is reduced to the sound of their breathing, the sensation of his mouth against her opening, his tongue inside her and the solid weight of his hands holding her still.

"Fuck." She groans again as he presses back inside. She squeezes her eyes shut, panting now.

"Fuck me Theta." The Mistress breathes out, not sure how much longer she can take his teasing. She swallows hard as he moves from her, running his hands down her thighs.

It seems like forever that she waits for him. She hears the quiet rip of a condom package and the soft slick as the Doctor coats his dick in lube. He gasps softly.

The bed shifts slightly. Cold fingers probe and the Mistress hisses in shock.

"Fuck that's cold!" She gasps as they slide in again. The Doctor says nothing, pressing his lips against her neck. He kisses her again and again as his fingers move. Gradually the lubrication warms and Missy sighs relaxedly.

"Theta…" She moans as he sits up again, fingers once again leaving a trail against her thighs.

He presses against her entrance and she breathes calmly.

"Fuck me." She says clearly.

Tenderly he fucks her, hands a welcome weight at her hips.

Only her addled brain prevents her from escaping her bonds to kiss him.

They sigh and groan, meeting each other as best they can.

"I love you Koschei." Comes the hoarse voice of the Doctor over the rushing in the Mistress' head, "I love you so much." He says.

"Theta!" Cries the Mistress, chest heaving as she comes, "Theta…" She moans as he comes too, head bowing to her chest. She knows that those two words convey as much to him as his did to her.

They both pant, laughing a little as the Doctor presses kisses down her neck.

"You're going to have to pull out quickly." She teases, tilting her head away from him.

The bed shifts again as he gets off of her.

"You weren't saying that a few moments ago." He retorts but Missy can tell he is smiling. She pretends to huff but can't hide the grin on her face.

"How are you wrists and legs?" He asks as he gets rid of the condom.

"Hm?" The Mistress shifts slightly, testing the joints, "Not too bad." With a clearer mind she begins working at the rope around her wrists. The knots are tied quite competently. Missy wonders momentarily where he could have practised before smirking.

"So- River enjoyed being tied up?" She calls out, unsure of where the Doctor is in the room. Suddenly a tension fills the room and the Mistress stills in untying her bonds.

"Please don't talk about her." He says quietly. For once the Mistress listens.

"Sorry." She speaks robotically and finishes freeing her wrists, "I forget." The words come out hollow. There's a slight indent where the rope was. Missy rubs at it a little before sitting herself up, knees in front of her chest. She slips the blindfold off of her head, squinting into the brightness, and unties the messy knot at the back. The ties around her legs are far simpler to deal with when her vision returns properly.

"I'm sorry." She says again, "When my own wife…" Her hands still and she drops them, looking at the side of the room he isn't in. They are both silent for a while.

"I didn't love her as much as I did you but it was enough." She continues, going back to working at the ropes around her thighs, "I loved her. You know that. You know I'm capable of it." She says as if to challenge him.

He is by her side, a hand on her knee. She looks up at him, looking somehow childlike despite what they had just done.

"It's okay. I know." He says, bending down to help her. The Doctor kisses at her temple on the way down.

They are silent as they untie her and silent as they apply lotion to the shallow indents from the rope, massaging the reddened skin.

They are silent as they lie together, the Mistress curled into the Doctor's chest with his arms around her.

"I love you Theta." Says the Mistress.

He pulls her closer, his head nestled in her hair.

"I love you too Koschei." The Doctor replies softly.