Continuity Note: This adventure takes place before Arc of Infinity. Contains spoilers for Big Finish audios The Deep and Circular Time.
Comparative Xenobiology Between Friends
Their visit to the fourth moon of Cheroelle had not begun well. The TARDIS had landed atop a great tree, a fact that she had failed to advise her passengers of and had resulted in the Doctor and Nyssa taking a rather unexpected tumble to the forest floor below upon exiting the police box's doors. Fortunately, the combination of the many branches they encountered on the way down and the lower gravity on the small moon meant that they were both merely bruised, not broken, when they landed. The situation deteriorated from there, when their abrupt introduction to the ground was punctuated by the arrival of a torrential downpour.
In the future, relative to their current temporal location, this moon would be colonised by humanoids from a neighbouring star system and host to a well-regarded biological research institute. Nyssa wasn't quite clear on whether or not that time would be considered in her future; the Doctor had been a bit vague on the dates. (With Traken gone, did she even have a temporal "home" to calculate such things from?) The Doctor had been keen for her to see it, but as ever, his piloting skills tended toward the erratic at times and they'd missed their mark by some years. He'd suggested an exploratory jaunt outside to have a look at the flora and fauna anyway and that was how they'd landed in this mess.
As it happened, in their attempts to locate something that might aid them in their efforts to scale the tree their transport had perched itself upon, they soon discovered the moon was currently inhabited with, among other things, a rather large predatory species that came very close to making an exotic meal out of the pair of them. The creature had exhibited, quite suddenly, the ability to propel an extraordinary quantity of corrosive fluid from its mouth, presumably with the intention of incapacitating its intended victims. The Doctor had taken the brunt of it, his larger frame shielding Nyssa's, which worked in their favour as at least one of them was left able-bodied enough to hurl a rock at the creature and drag the Doctor to safety.
They stumbled blindly through the vegetation for a few minutes before coming upon the entrance to a cave large enough to serve as shelter but small enough to be concealed should the creature decide to follow them. It had retreated in surprise when Nyssa had thrown the rock at it, but she couldn't hope that it would discourage it permanently.
Once inside the cave, the Doctor clawed at his clothing, frantic in his desperation to remove the soaked garments. Whatever the creature had sprayed him with was eating through the organic components of the fabric and had begun a painful assault on the time lord's skin. Nyssa did her best to assist him, while being mindful to avoid contact with the noxious substance herself. He'd been lucky to have been wearing so many layers; as they stripped him off, Nyssa could see angry red chemical burns forming where his skin had come in contact with the stuff.
When they'd removed everything that had been contaminated and scrubbed him clean as best they could, the Doctor collapsed on the cave floor and lay shivering, half curled up on his least-injured side. Nyssa had seen him recover from serious injuries before, but his condition concerned her; the Doctor had second-degree burns covering a significant portion of his torso and left thigh. His dark blue eyes were glassy and distant with pain but he blinked in recognition when her face came into view.
"Nyssa," he mumbled as she attempted to cover him with her velvet jacket and what little she could salvage from his own discarded clothing. It left her wearing just a thin vest top with her trousers, but she didn't have severe burns interfering with her body's ability to regulate its own temperature unlike the Doctor's at the moment.
"It's all right Doctor, we're safe for now," she assured him, not certain if this was a lie, "just rest; I'm right here, I'll take care of you." She pushed a clump of damp fringe back from his face in a soothing, motherly gesture and he sighed at her touch and closed his eyes.
Given her past experience, she suspected he would likely be unconscious for a while, as his body did the hard work of repairing the damage, so she set about the task of securing their temporary lodgings against further unpleasant surprises. The mouth of the cave was narrow enough that an armful of hastily gathered foliage was sufficient to disguise it from view. She saw no sign of the creature that had attacked them but readied a small arsenal of loose stones just inside the entrance, in case it reappeared and she had to defend them again.
With the only opening to the outside covered, the cave was much darker. A careful search of what remained of the Doctor's pockets did not produce a torch but he had been carrying a small matchbook she suspected he'd picked up in that pub on Earth they'd been dragged to by his new cricket club mates. He'd scowled when one of them had offered her a pint and she'd accepted it, but didn't say anything. The pint wasn't to her taste, but she didn't tell him that.
Ever since Stockbridge, he could become quite tetchy at the oddest times, though it hadn't escaped her notice that it often coincided with other men paying her attention. If she didn't know him better, she'd suspect him of acting out of jealousy, but since this was the Doctor after all, it was more likely either a misguided sense of obligation to protect her, as an elder sibling or parent might do, or his own ego bristling at not being the centre of attention (admittedly less likely with this incarnation than the first one she'd met, but still a consideration).
The only problem was, there was nothing in the cave dry enough to build a fire. They were shielded from the heavy rain at least, but nearly every surface inside the small space was damp. Just beyond where the Doctor lay, against the far wall, a natural spring bubbled and flowed out through a slim crack in the rock. At least their shelter was enclosed enough that she could be reasonably confident that they weren't about to be joined by any other new and unfriendly examples of the local wildlife. Sitting down and pulling her legs against her chest protectively, Nyssa settled in to wait for the Doctor to wake up.
Several hours later, it finally stopped raining and the meagre light penetrating into their rocky alcove increased. Nyssa had slept only fitfully herself, waking periodically to check that the Doctor was still breathing. With the storm subsided, she decided to take a chance and shift the leaves a bit to let in more ambient light so that she could examine him properly.
Without his many layers of clothing, the Doctor looked very young. The daylight revealed pale skin dusted with freckles and a lean athletic body that was slimmer than she might've expected. He was cool to the touch, but not unusually so for the Gallifreyan; she knew his natural body temperature was lower than her own. Rolling him gently to his back so she could look at his wounds, she was relieved to see the burns had faded to a faint pinkish discolouration on his chest. She moved aside the bits of clothing she'd covered him with earlier to check that his thigh had similarly healed. In doing so, Nyssa inadvertently brushed against a portion of the Doctor's anatomy that she'd quite forgotten to expect, and pulled her hand away quickly in surprise.
The urgency of the situation earlier had leant her the clinical detachment necessary to respond quickly and tend to his wounds without blinking, but now, with him laying nearly healed in front of her, it suddenly occurred to Nyssa that the Doctor was quite naked. And, given the evidence before her, was most certainly a fairly standard humanoid male. Not that she'd particularly expected anything different, mind you, but he was an alien after all, and it was quite a different thing entirely to have it all laid out, so to speak. She bit her lip, feeling like a voyeur, and resisted the sudden and inexplicable urge to touch him. Instead, she grabbed the nearest bit of stray clothing, which happened to be her jacket, and dropped it over him to preserve his modesty.
This was, of course, the point at which the Doctor regained consciousness and opened his eyes to see Nyssa, blushing furiously, kneeling at his side and attempting to cover him in fragments of cloth. It occurred belatedly to his confused mind that this, and the chill touch of air on his exposed skin, meant that he was missing his trousers and everything else he normally wore. Quite involuntarily, he felt himself blushing as well under her partially averted gaze. She was nearly half undressed herself and more than a little dishevelled from their dash through the forest earlier.
Noticing this did not help matters as it only encouraged an insidious little voice in the back of the Doctor's brain that noted that seeing more of her body like this was very nice indeed. He clamped down on that thought hard, before any other parts of himself started getting ideas. Nyssa was a friend and travelling companion; it would be entirely inappropriate for him to entertain thoughts of anything else. His appearance did not alter the difference in their ages and that he'd long ago made himself responsible for her. Besides which, any interpretation of her attention as anything other than simple curiosity was merely wishful thinking on his part.
When he'd regenerated surrounded by youth and had become one himself again, it had unexpected consequences. Other humanoid species being what they were, especially humans themselves, it wasn't as if he'd never been treated as an object of sexual interest, but it had been quite a long time since it happened this regularly. He didn't know if it was a quirk of this body that made him shy or simply that, lacking practice, he had no idea how to deal with it, but he found the whole situation quite embarrassing. What made it worse was that despite this, his younger body responded to the attention he now got and perhaps even, on some level, liked it and wanted more.
To combat this, he set careful boundaries for himself in this body, lest he lose perspective and forget that he was not actually the young man he appeared to be. Kept himself ever so slightly distant so that his companions wouldn't forget either. But that had never truly worked with Nyssa. They were far too alike and his concern for her well-being after what had happened to her father, and then her world, was too great for him to maintain his emotional distance. And in the years that she'd now been travelling with him, she'd grown into quite the resourceful and brilliant young woman. It was perfectly natural for him to be fond of her. It didn't necessarily imply anything more than close friendship that the thought of her eventually leaving him caused an anxious twisting sensation in his gut, did it?
That little voice quietly reminded him of the last time he'd felt like this, and what it had meant when Jo left him. He'd been a miserable sod for weeks after that. And it had been nearly as bad when Romana had departed, but then, he expected he'd see her again someday, no matter how unlikely a prospect it seemed. Romana was the sort one shouldn't underestimate. It always hurt when his companions left him to get on with their lives, he told himself, but it was, on the whole, for the best. For most beings, wandering through the fourth dimension was not a lifetime pursuit, nor should it be.
As none of this was particularly relevant to his current situation, flat on his back in a wet lunar cave, the Doctor thought it might be best if he focused on the present instead and actually said something aloud. Nyssa would no doubt be wondering why he'd been staring at her for the past several seconds.
"Ah, hello, Nyssa," he managed. "Good... morning, is it?"
"Doctor. You're feeling well again I take it?" she replied, carefully not looking at anything below his shoulders.
He pushed himself up onto his elbows, mindful not to shift the velvet jacket laying across his lap, and had a look at himself. He couldn't sense any internal damage left over and the newly healed flesh on his torso was merely ever so slightly flushed and shiny. If he hadn't known that he'd been badly burned, he doubted it would be particularly noticeable.
"Yes, it would appear so," he reported. "Thank you for getting me to safety; that was quick thinking back there. I'm afraid the guidebooks failed to mention that particular species when they listed the local wildlife to watch out for. I suppose my clothes are a lost cause at this point?"
She nodded and reached over him to lift up a ruined cricket jumper. The creature's attack had fully dissolved most of the front of the garment. "I'm afraid your shirt and trousers aren't much better. We might be able to do something with the coat," she suggested.
"Well, at least my socks appear to have survived," he joked, wiggling his feet and prompting a smile from Nyssa.
This close to her, he noticed the large bruise on her shoulder as she sat down again and the dark circles of exhaustion under her eyes. He stopped her with a gentle hand and sat up fully to examine her with concern. "Are you all right? I should've asked sooner; harrowing business with that creature after what was quite a fall from that tree..."
"I'm fine, Doctor. Just a bit tired, is all," she answered him, but he didn't believe her.
Scooting himself backwards so that he was sitting up with his back pressed against the cave wall, he took her hand and encouraged her to join him. When she did, he pulled her in to rest against his chest without thinking. Surprised, she held herself stiffly in his arms for a moment and was about to speak when he beat her to it, anticipating her protest.
"The TARDIS isn't going anywhere; we have time for you to get some sleep before we head back. I know you've been holding vigil while I recovered, don't try to deny it. I'm not terribly warm, but I should imagine I make a better pillow than a damp stone floor. Do let me take care of you Nyssa, it's the least that I owe you." It was not the first time he'd made such an offer to her, but he realised he'd been much more fully clothed on those occasions. Hopefully she'd take it in the spirit he intended and not let that detail dissuade her. He smiled when she relaxed against him without further complaint.
While she slept, the Doctor had time to think about their predicament and devise a plan for returning to the ship safely. He'd seen some vines growing in the forest before they'd been attacked that might do for constructing a rope ladder. They could then use that to gain access to the lowest branches of the tree the TARDIS was perched on and climb up from there. There was just the small matter of that creature and defending themselves should another encounter be unavoidable. He noted the rocks piled strategically by the cave entrance and patted his clever companion's back fondly.
Despite their less than ideal location, the presence of a warm body next to his own was oddly comforting and soon the Doctor drifted off again as well.
Nyssa woke to find that she'd snuggled closer to the Doctor in her sleep and wrapped her arm around his bare waist. With her head on his chest she could hear the double beat of his hearts clearly and feel the gentle rise and fall of his ribcage as he breathed. It reminded her of when she'd tried to repair the chameleon circuit in the TARDIS and it had failed spectacularly; they'd ended up standing waist-deep in the ocean and he'd shyly asked her to listen to his heartbeats for him so that they could use the familiar cadence to call to the wayward timeship. Yet this felt much more intimate. It was strange that the absence of a soaking-wet shirt between them could make all the difference.
The Doctor was normally quite reserved when it came to contact. Nyssa could hardly blame him for it though; since his regeneration, nearly every person to invade his personal space had done so with violent or malicious intent. His companions couldn't have made it easy for him either; Tegan spent much of her early time on the TARDIS bickering with him and Adric, prior to his tragic death, had reacted poorly to his mentor's sudden change in appearance and temperament. Nyssa knew that she could be distant herself at times; as a Consul's daughter, despite - or perhaps because of - Traken's peaceful and orderly nature, she had been taught from an early age the importance of maintaining one's composure in even the most difficult of circumstances.
She knew she was stalling for time, pretending to still be asleep for a few moments longer to stay close to him, but wasn't sure why she was doing so. Something about this was vaguely thrilling, like the rare occasion when she'd been a child and done something forbidden and gotten away with it. Physical affection from the Doctor was infrequent, though he seemed more at ease with showing it to her than anyone else.
She couldn't help but compare his body to Andrew's as she lay there; a dangerous line of thought as it placed the Doctor in a very different context than she felt was entirely appropriate. Though their relationship had evolved from one of a guardian and his ward to colleagues and friends, it seemed overly familiar to mentally associate him with that aspect of her life. And he was far older than her, no matter how young he appeared.
Even knowing this, still she continued. Surely, scientific interest was a valid excuse? The Doctor was taller and broader through the shoulders than Andrew had been, and while her former lover had had soft brown hair scattered across his chest, the Doctor was smooth. Forgetting her pretence of slumber in her fascination, Nyssa ran her hand down the firm flank before her, wondering if he had the random chance of regeneration or his fondness for sport to thank for his trim build. She suspected it was a little of both.
It was really quite incredible how similar he was to the human man she'd known and her own people, but the subtle differences were there if you knew where to look. She counted his ribs as they slid under her curious fingertips; one more than a Trakenite would have. Would he also have an additional vertebra in his spinal column? She'd never thought to ask. How many did humans have? She couldn't remember if she'd ever checked.
It wasn't until the Doctor made a low groaning sound that rumbled pleasantly in his chest that Nyssa realised that she'd been stroking him as one might a pet. Startled, she swiftly withdrew her hand from his chest and tried to sit up. She was stopped by an arm coming up her back to curl possessively around her. Embarrassed, she looked up at the Doctor to find his eyes were still closed. From the vaguely pleased expression on his face, she didn't believe he was entirely awake just yet.
He made another contented low hum in his throat and his other hand jointed the first, this one kneading gently at the muscles in her back. That felt simply wonderful and she pressed herself tighter against him in response. His hands moved lower and slipped under the hem of her top; the thread of desire accompanying his movements was shockingly unmistakable. Her own heart was beating faster now of its own accord, his cool touch inspiring a myriad of ill-advised thoughts. She didn't want this to stop, but at the same time, she didn't wish to take advantage of the Doctor. He was a dear friend for whom she held the utmost respect and this was most unlike him. What if he were dreaming of someone else and had mistaken her for a lost love? They'd both be mortified.
"Doctor?" she whispered.
"Mmm?" came his rumbled response. He still hadn't opened his eyes or stopped his wandering hands.
"Doctor, you need to wake up," she tried again, louder this time.
Finally, he did open them and deep blue irises met and focused on her own. "Nyssa? What...? Oh." He swallowed heavily as he took in their compromising position; it hadn't been just a pleasant dream then. Oh dear. Silently cursing himself, he hoped desperately that Nyssa would forgive him the impropriety and hadn't yet noticed his over-eager body's most prominent physiological response to her. Acute embarrassment rerouted some of the blood flow, easing the problem. He needed to apologise or do something, anything, but he was frozen with indecision.
Nyssa didn't need her empathic abilities to decipher his flustered reaction; he was panicking, just as she'd expected. The undercurrent of desire she'd sensed from him before he'd been properly conscious had not entirely gone away though. That was interesting.
She'd always assumed, and he'd never said otherwise, that he wasn't particularly interested in sexual interaction. She didn't know what customs Gallifreyans observed regarding sexuality, but the Doctor had always seemed vaguely uncomfortable being subject to that sort of attention. When she'd witnessed others express such an interest in him, he tended to be either oblivious to it or awkward. He might have had any number of biological, sociological, or personal reasons for his behaviour, but it had seemed too invasive a question to ask of him simply to satisfy her curiosity. Now here he was, naked in her arms, showing classic signs of sexual attraction; perhaps she'd been too hasty in her judgment of his preferences.
She didn't especially want or need a romantic relationship with the Doctor; she loved him, certainly, but not in the sense of infatuation, not any more. She knew him well enough now to know that while he was undoubtedly capable of passion, and could be remarkably sweet in unexpected ways, he would be ill suited to it in the long term. He spent his life running from one adventure to the next, never remaining in the same location for very long; he wasn't the sort of man who could settle down with a wife and raise a family. She would eventually find her own place in the universe and they would part ways. However, this was not to say that she didn't find the prospect of further exploration appealing.
Her relationship with Andrew and the day to day realities of life travelling in the TARDIS had given her a new perspective on the virtues of spontaneity; this made her bold when a younger Nyssa might have retreated. A physical relationship had been an enjoyable experience the last time she'd tried it, even if it had concluded on an emotionally bittersweet note. As long as they were both honest about their intentions afterwards, Nyssa could imagine sharing that with the Doctor. He really was very attractive and, most importantly, she trusted him. If they tried and it went poorly, she knew they could mark it as a failed experiment and move on without severely damaging their friendship.
Whether it was down to curiosity or reawakened hormones, Nyssa decided she wanted to explore this with the Doctor, assuming he was genuinely interested and it wasn't simply lack of food or proper sleep interfering with his behaviour or her perceptions. If they were going to do anything together, it would be up to her to initiate it; fully conscious, the Doctor would be far too polite to act without explicit consent on her part. She resolved to give him a clear opening to take things further and see what he chose to do.
"You needn't worry about apologising to me, Doctor," she assured him, "you haven't done anything to hurt me. In fact, I rather liked it; you could continue, if you want."
This was evidently not the response that he'd imagined she'd give. She had scarcely ever seen the Doctor look so dumbfounded before.
"What? You... what?" he stammered, eyes wide.
To stop him floundering for another minute, Nyssa leant forward and brushed her lips against his tentatively. His mouth parted slightly and he returned her pressure for a few seconds before dragging himself away from the kiss to speak.
"Nyssa," he breathed, "I... we can't... it's not... you're too..."
"Doctor." She fixed him with a firm stare. "We're friends, are we not? I'm not suggesting anything more than a mutually pleasurable experience. I'll understand completely if you'd rather not, but please do me the courtesy of recalling that I am capable of making such a decision for myself."
The Doctor inhaled sharply and gazed at her with an awestruck expression for a few beats before screwing up his courage and throwing caution to the wind. He bent forward and kissed her hungrily, like a starving man let loose on a feast. His mouth was just as cool as the rest of his body, which made kissing him strange at first, but no less pleasant.
Nyssa wrapped her arms around him and pulled herself up so that she was straddling his legs to get a better angle. His hands detangled themselves from her hair and slid lower, in search of new places to explore. In stark contrast to his kisses, the Doctor's hands were gentle and cautious as he slid them up under her vest top.
"You'll have to tell me what you like," he broke the kiss to pant against her collar bone, "I'm out of practice and less familiar with the er, relevant aspects of Trakenite biology."
She laughed and adjusted the position of one of his hands. "Certainly. I'm finding it most agreeable so far. And you'll do the same for me?"
He nodded eagerly and helped her remove her top.
For someone who claimed to be out of practice, the Doctor had certainly acquitted himself well, in Nyssa's opinion. He followed her directions carefully and with an enthusiasm he normally reserved for new discoveries, which, in a sense, she supposed this might qualify. For her own part, she'd focused on making sure he enjoyed himself as much as she was, rendering him nearly incoherent by using her empathic talents to reflect back at him the pleasure he was giving her.
The cave had warmed considerably and both of them were still sweating from the exertion as they lay next to each other, staring up at the swirls in the stone roof of the cave, limbs comfortably tangled in the afterglow of a successful experiment in interspecies relations. The Doctor held her hand in his own, their fingers gently interlaced, the pad of his thumb tracing circles on her palm as they contemplated what they'd done. The situation suddenly struck Nyssa as unbelievably surreal and she broke their companionable silence with a fit of giggles.
"Surely, I wasn't all that bad." The Doctor gave her a mildly affronted look but she could hear an edge of humour in his voice as well. She shook her head, but his expression only made her laugh harder. Her mirth was contagious, and the Doctor couldn't help but join her.
When they'd calmed down, Nyssa pressed a kiss to his cheek and said, "thank you, Doctor; that was brilliant. We ought to try it again some time, under better circumstances. That is," a small measure of doubt crept into her voice, "if you wanted to." She brushed a stray brown curl away from her face with a soft smile and reached for her clothes.
He caught her arm and waited for her to meet his gaze again before he spoke. "I... think I'd like that," he confessed. "Are you sure though? That it's what you want? I'm not very good at this." He turned his head slightly away from her. "I don't make a habit of getting involved with my companions, broke my own rules today, in fact. I'm not saying I regret what we did," he assured her. "But things... inevitably end up getting complicated, feelings hurt, that sort of thing. I never intend them to, but I'm not, that is, I can't..." he trailed off helplessly.
"I know, Doctor," she told him. "I never would have suggested it without considering that. I know you care about me, as I do you, but I really don't expect anything more than friendship. I had a lovely time today; if we do this again, wonderful, if not, we can put this behind us." She smiled tenderly and added, "if I've learned nothing else travelling with you, it's that nothing is permanent, and we should enjoy what we have while it lasts."
Her words reminded him of all the tragedy she'd experienced in her twenty-ish galactic-standard years of life. Nyssa was far stronger than most people he'd met in his considerably longer journey through the universe. Stronger than he was sometimes, the Doctor was ashamed to admit.
He wished he knew if that was how she genuinely felt, or if she was just pre-emptively protecting herself from emotional trauma by setting low expectations for him to meet. No, he didn't think she'd lie to him about this, not when it would be all too easy for her to end it. The Doctor wouldn't be able to forgive himself if he hurt her, but he was beginning to realise it might be his own hearts that were in the most danger here. He swallowed heavily; was it worth the risks to continue? He'd already gone further than he should've, if he'd wanted to avoid any complications.
Nyssa watched him quietly. When the Doctor was silent for several moments; she feared she'd inadvertently given him second thoughts until he lifted a hand to stroke her face. "Shall we play it by ear then?" he suggested. "If either of us changes our minds, we'll go back to how we were before, no explanations necessary. Until then," he kissed her again, "we can try being more demonstrative with our affections on occasion and see where that takes us?"
"That sounds fine," she agreed. "Can we see about getting back to the ship now? As educational as this adventure has been, Doctor, nothing would make me happier than a meal and a hot bath."
"A splendid idea," the Doctor remarked with a grin and released her.
Nyssa dressed while the Doctor did his best to construct some measure of coverage for himself out of the remains of his own garments. He managed something resembling a kilt using the intact half of his braces as a belt. His coat had a massive hole eaten through it down the left side, but was more or less wearable; it should keep the rain off his back, if nothing else. Nyssa had the good graces not to laugh at him, but the Doctor was glad that they were alone on this moon. His rather doubted his dignity would survive having an audience when it came time to start climbing trees in this, as his ingenuity had not extended to undergarments.
The return to the TARDIS was wet, but mercifully uneventful. They were able to assemble a suitable ladder out of vines and climb the tree without interruption. The Doctor made a mental note to add a reasonable length of rope to his pockets at the earliest opportunity.
Once they were safely back inside the TARDIS, he gave the console a disgruntled thump for nearly getting them killed, to which his ship replied with the telepathic equivalent of a faux innocent shrug and what felt like a vaguely suggestive remark regarding how he'd spent his time over the past day. Feeling his cheeks redden, he ignored her teasing and set them to drift in the vortex for a while to stay out of trouble. The ship obliged him with her characteristic groan and wobble as they dematerialised.
Clearing his throat, he met his companion's puzzled look with a pleasant smile. "Fancy a cup of tea, Nyssa?"
a/n - This started as a vaguely cracky idea to amuse myself and accidentally grew a plot because I apparently can't just write porn. (This might be a good place to note that this actually was more explicit in the first draft - I edited it b/c it felt awkward; sorry smut fans!) I'll admit the "involuntary/unexpected nudity leads to sexy times" trope is pretty cliché, but it's one of the few ways I could imagine these two ever getting together, despite how hard I ship them. They're both too polite / oblivious to initiate anything without a serious nudge in the right direction. (One of the reasons this story is so long is because it felt wildly out of character for either of them to jump right in without over-thinking it.)
I liked the idea that Nyssa's no longer the innocent she once was when it comes to relationships after the events of Circular Time and she's well-aware that anything with the Doctor would be temporary at best, but that doesn't mean she can't enjoy herself. Contrast with the Doctor, who is very probably more smitten with her than he'd admit to even himself, and decides he can totally handle a friends-with-benefits arrangement, and you have a recipe for the incredibly heartbroken look he gives Nyssa when she tells him she's staying on Terminus.