She makes it to Thursday evening before giving in. She'd gone back and forth, arguing with herself, trying to convince herself that it was a bad idea to see her again. But then, surely there was no harm in it? There was an attraction there, yes, but it wasn't as if she was madly in love. This was her boss, after all, this was stern, uptight, angry Dr Elliot.

And OK, maybe the discovery that she was also sweet, loving, funny Caroline had won her over more than she would have expected. But that was all that had happened and all that would happen. The danger was perhaps more present now that she knew she was interested in women but that didn't mean that she was interested in her. Besides, she couldn't see a woman as private as Caroline starting a workplace relationship in the first place.

So she was as safe as she had always been, only now she really wanted them to be friends instead of distant colleagues. Something about the combination of Dr Elliot's tough exterior and Caroline's softer centre had genuinely moved her, and although Kate liked an awful lot of people and had many friends she didn't feel that kind of deep emotional connection very often. It would be a real shame to ignore it simply because of a physical attraction that would never go anywhere.

With her reasoning carefully laid out in her head she writes her a short, breezy note asking if there might be a possibility of any more roast dinners and then spends most of Friday in town. When she gets back and sees the note pinned to her door she tries to ignore the quickening of her heart, but she can't keep the smile off her face when she sees the words "Same time Sunday? See you then unless I hear otherwise" in Caroline's distinctive handwriting.

After a very dull Sunday morning trying to wrestle her finances into shape she waits until 1.29pm and then walks down the corridor, a bottle of wine in her hand partly as a gift and partly an excuse to drown out the mild nerves that are threatening to spoil their fun.

She needn't have worried, however. The meal is as delicious as last time and Caroline is endlessly fascinating, able to talk articulately about anything from chemistry to literature to school governance. It's only after they've finished eating and they're settled comfortably on the sofa that she realizes she hasn't asked her about William.

"So…tell me. How it's been, this week, for you? I hope you've been all right, I was thinking about you."

"Oh, that's nice, thank you," she says, looking a little embarrassed. "But I've been fine, fine, no problem at all, it was a massive over-reaction as I'm sure you noticed. It's not like he disappeared into thin air, he's only a few hours away. Totally daft, the whole thing."

"Not daft at all. You must miss him, though. There's something special about a mother and her son, that bond, isn't there? I mean fathers and son too, I suppose, all parents really, but when there's a really strong bond between a mother and son it's so lovely to see, especially when it's still there when they're adults, a great strapping lad who really loves his mum, it's very…"

It's only the sight of Caroline's tears that make her realize she's being horribly insensitive.

"Oh, Caroline, I'm so sorry, what a stupid thing to say. I'm sorry. Come here."

She holds out her arms and Caroline comes to her without hesitation, resting her head on her shoulder. Kate holds her tightly, trying to convey her compassion, trying to make it all a little easier to bear.

Thirty seconds pass, a minute, two. It feels strangely normal to be holding her, although of course it's not the first time she's comforted her like this. She's so warm, her body heat radiating out to every part of her body that it touches.

After another minute or so there's no indication that she's still crying so she begins to think about pulling away, but then decides to let the other woman take the lead. After all, if her marriage is long dead and her last love affair was several years ago she might be a little starved of affection – and surprisingly enough, affection was now something she could genuinely offer her.

It won't do any harm to give her some comfort. And there was surely no need to feel guilty about the way her own body was responding to the closeness; that was only natural when they were hugging so tightly.

Another minute passes; they've been holding each other for too long now to pass it off as a casual hug between colleagues. They're friends now, she was sure of it, even if she couldn't quite pinpoint when it had happened. She feels a warm glow at the thought.

Finally, after another few minutes, Caroline begins to move. She's braced for the slight awkwardness that's surely coming next, the apologies from a proud woman, but then she realizes that she isn't moving away at all. Instead she's gradually moving backwards on the sofa, lying down against the arm-rest. And gently taking Kate with her as she goes.

Alarm bells sound loudly in her head, but her body seems to be over-ruling them and she lets herself be manoeuvred into place. Their new position is incredibly comfortable – her head is now resting on Caroline's chest and she's wrapped in a tight embrace that feels so pleasurable she can't find the will to move. And it's not just the simple pleasure of another body – a steady pulse of desire together with the racing of her heart let her know very clearly that her attraction is building by the second.

The potential for later awkwardness has just doubled, but she can't quite bring herself to care. The embrace feels so natural, so right, as if she had been dreaming of lying in her arms for months. It's confusing, unnerving, and perfect all at once.

Time passes, peacefully, blissfully. She feels herself start to drop off to sleep but she fights against it, wanting to stay awake to absorb as much of the pleasure as she can. Caroline remains almost motionless beneath her, the rhythmic rise and fall of her chest the only movement, until a hand slides gently into her hair and begins a soft caress. It's all she can do not to sigh in pleasure as the fingers sift through her hair and tenderly run across her scalp. Whatever moments of social tension might come later, there's no way she's moving now.

"Kate? Kate?"

Consciousness returns to her gradually. The tentative sound of Caroline's voice registers first, followed by the warmth of her body and then the fact that she can barely see, the light in the flat almost entirely replaced by gloom.

"Are you awake? I'm sorry to disturb you but I should probably put some lights on."

Caroline's arms loosen, releasing her. It takes a worrying amount of willpower to sit up and move away from her but she manages it, grateful for the darkness that's hiding her incipient blush – at least for the moment.

"What time is it?" she whispers.

"Uh…I'm not sure, exactly, I fell asleep myself. Must be quite late if it's this dark."

She can just about make her out as she walks carefully over to the light switch.

"Ow! Shit and double shit."

"Are you OK?"

"Stubbed my toe. Damn it. It's that stupid bloody umbrella stand my mother gave me, it's pure evil, I swear it lies in wait for me. Must be made of bloody concrete. Concrete and evil."

The light is turned on and they both blink slightly in the glare of it. She walks over to her, a nervous knot in her abdomen.

"You didn't hurt yourself?"

"No, no, it's fine, I'm fine."

They meet each other's eyes, and there it is – the awkward moment she knew was coming. Caroline is visibly nervous; Kate doesn't know what to say. The moment stretches out uncomfortably, the tension increasing with each second, until Caroline finally breaks the silence.

"Same time next week?" she says softly.

Alarm bells sound again. But standing there, faced with her anxious beauty, there's only one answer she can give.

"I'd like that," she says.