As the months and years passed, it became clear that Matt was not destined to become just another of Nikki's (many) disastrous relationship decisions. Against all the odds, they did not fall out over Nikki's refusal to move to Washington or Matt's decision to try for Congress. He didn't turn out to be a cheater or a liar or a sleezy politician, or indeed anything other than who he was – a perfectly pleasant, kind-hearted man who was deeply in love with Nikki. His children didn't take an instant dislike to his British girlfriend; his ex-wife didn't put up any opposition; his staff entirely failed to freeze Nikki out on her visits. And – most importantly of all, from Jack's point of view – he never put unfair pressure on Nikki to leave her job and join him. Jack never heard so much as a raised voice during Nikki's phone calls – those that he overheard, anyway.

By all accounts, it was the perfect relationship – marred only by distance. If they were on the same continent, they'd probably be married by now.

There had been some tension between the couple concerning the fatal plane crash that Matt should have been on. As far as Jack knew, Matt had eventually told Nikki, but whether he had or not, things seemed to settle down once more.

And then there was the case in Brighton. Nikki had seemed distracted and a little pale – just off in some undefinable way. He'd had his suspicions when she'd raised the topic of having children. In his experience, once she was on a case, Nikki tended to be extremely focused. It was highly unusual of her to start talking about something else entirely, so the so-called casual chat raised his suspicions. If she was thinking about having children, it wouldn't be simply that – not mid-case. It would be because the thought had been forced upon her. And he knew of only one reason why that might be…

Jack had resigned himself to the inevitable by then. He had no illusions – if Nikki and Matt weren't going to work out, they would have split long before. If Nikki had been attracted to Jack, either before or during Mexico, there was no sign of any attraction now. Their friendship was firm, and they'd resumed their habit of meeting for drinks or dinner on regular occasions. The only real difference now was the need to plan ahead based around Nikki's and Matt's regular flights between London and Washington. That and…the fact that Jack and Nikki were both less inclined to be quite as tactile as they used to be. When he'd held her hand walking along the river on the day Matt had departed, Jack had intended to send a clear message – that he still cared about her in a platonic way and that his affectionate gestures wouldn't stop even though she was now in a relationship. She had seemed to accept that, but there was some consciousness in her gestures now - some kind of awareness of what might, and might not, be appropriate. It pained him, although he could understand.

But…Nikki in a long-term, albeit distant, relationship was one thing. Nikki as a pregnant woman, a mother-to-be, was quite another. If it was what she wanted, he would be glad for her, but how could she possibly stay on at the Lyell? Unless Matt abandoned his ambitions and moved over, she would be bound to move over there. She'd really have no choice – not if she wanted Matt in his child's life. They would, of course, get married and live happily ever after. She'd make the perfect Congressman's wife.

The thought that he wouldn't get to see her almost every day of his life was unbearable. He knew by now that he still loved her - would probably never stop loving her. It was hopeless, of course, and he'd resigned himself to knowing that nothing would ever come of it. Getting to work alongside a Nikki who didn't share his feelings was still preferable to never seeing her at all.

It was a relief when nothing came of the motherhood talk, but then there were other crises. There were the accusations that her personal life was affecting her professional judgment, whether due to fatigue from frequent travel, distraction, or arrogance and over-confidence in her own abilities. It infuriated him to see detectives rolling their eyes at Dr Alexander or being overtly hostile, not least because he could see it affecting her confidence. He was certain that there must have been times when resigning her job and moving to Washington would have seemed extremely attractive to her – luckily for the Lyell (and for him), she showed her familiar grit in facing down her detractors.

Although he was relieved, he was also surprised that nothing seemed to change for Nikki and Matt. They were apparently happy to carry on as they were, and Jack couldn't understand it – not least because if Nikki had declared her love for him, he'd probably have been buying the ring within a few months, if not weeks. He didn't get Matt. It wasn't that he didn't respect the man's political ambitions, but… All he knew was that if he, Jack, was in Matt's position, he would have followed Nikki anywhere. Nothing – and certainly no career ambition – would have kept him from her side.

But it really was none of his business – and in any case, Jack increasingly had other concerns on his mind.

His father was growing frailer. Typically, Conor Hodgson was insisting on maintaining his independence and staying in his own flat. Jack had made tentative enquiries at a few residential care homes, but so far without much intent. He sensed there'd be a serious battle of wills if it got to the point where a decision was needed. They hadn't talked about it, but Jack knew his father had a notion that Ryan might need somewhere to stay once he was released from prison again – for this reason alone, Connor wouldn't be keen to sell up and move into sheltered accommodation. And, following the case involving abuse and murder at the care homes, Jack himself abandoned the half-hearted plan. He was uneasy at the thought of Ryan moving in with their father, though.

More and more, he found his spare time taken up by his father – driving him to medical appointments, doing his shopping, simply popping over whenever he could to make sure Connor was eating properly. He'd been on the occasional casual date and even more occasional one night stand, but nothing had been serious since his split from Naomi – and that wasn't just because of Nikki.

Jack had always felt a sense of responsibility for Connor since his mother's untimely death - in a sense, he'd often felt like a single child, since he couldn't rely on Ryan to offer any support. However, the burden felt heavier now. Connor had been a tough father in many ways – taciturn, critical and slow to show affection – but he'd been a strong and reliable presence during Jack's childhood, and Jack had always felt loved and supported in a quiet way, even after their falling-out over Katie. After his wife's death, Connor had held himself together – moving from Yorkshire down to London following retirement to be closer to his sons. He'd carved out a social life for himself, made some good friends among the Northern Irish community in Northwest London, and had kept active with frequent walks in his old age. He'd seemed determined not to be a burden on his son – and, until recently, Jack had had no concerns.

And then, out of nowhere, Connor had had a health scare, and it seemed to have dented his confidence. He hardly ventured out at all now, even though the doctors had told him that light exercise would do no harm. He grew nervy and bad-tempered – Jack often had no idea what to expect when he turned up at Connor's flat. Sometimes, his father would berate him for "making a fuss about nothing"; other times, he'd accuse him of not caring – "what if I fell and no-one came for hours?". Some days, Jack could do nothing right – Ryan, in his enforced absence, became the golden boy. It was always there, in the room, though never mentioned – if Jack had been honest about his role in the fight, where might Ryan be now? It didn't help Jack feel any better about his brother's current incarceration.

Sometimes, when he mentioned his concerns about Connor at work, he fancied that Nikki was biting her lip not to say something she might regret. Of course, with her own difficult family background, she was more likely to sympathize with the offspring of a dysfunctional family (although privately Jack didn't feel the Hodgson's were that dysfunctional, compared to many families he'd encountered through his work). He didn't know much about her childhood as she was extremely close-lipped, but he knew that her mother had died young and that her father had been no great loss, forcing her to grow up extremely quickly. Clarissa had said it, all those years ago – an old head on young shoulders. With her background, she was inclined to be cynical about fathers in general, and he also knew that she could never entirely forgive Ryan for Jack getting knocked down and badly injured. It warmed his heart to know she'd always have his back in any argument, but she could hardly be described as unbiased.

Clarissa's experience was different. Even if her mother wasn't the absolute saint she clearly had been before dementia had taken her, Clarissa been forced by circumstances to be closer to her than most children. For the cynic she was, she was surprisingly soft-hearted towards parents and their foibles, and was particularly fond of Jack's dad. She was sympathetic with Jack's dilemma, but clearly didn't approve of moving Connor to a care home – with her own fears, that was perhaps not all that surprising. He knew that were it not for her disability, she would have hesitated in moving her mother to one, despite the dementia, and she was assiduous in visiting her and making sure the nursing care was of the best quality.

He witnessed Clarissa's determination even more while Penny Mullery was dying in hospital – the pain of having to make tough decisions for someone who could no longer consent, the instinctive desire to keep her alive no matter what the cost, and the sheer agony of eventually having to accept the inevitable.

Jack had felt clumsy and helpless and had never been more grateful that she had Max's loving support. In some ways, her mother's death made him more aware of how he and Clarissa had grown apart in recent times. When they'd arrived at the Lyell, she'd been his closest friend and confidante. They'd been students together, had kept in touch when he'd returned to Yorkshire, and she'd been there to offer him a spare bed and help to rebuild his life in London after his messy public resignation. When Leo had offered him a position at the Lyell, he'd determined that he couldn't make a go of it without Clarissa's steady presence. However, as the years passed, Jack had grown closer to Nikki, and she was now his first port of call in any crisis. He felt guiltily aware of Clarissa's admission that she was a little jealous of their close relationship. Even the disagreement they'd had when he wanted her to go off work to spend time with her mother shook him up and hurt him more than he cared to admit. The worst of it was that he slightly agreed with her – sitting for hours with an ailing parent was stressful, whether or not that parent recognized you. He couldn't help wondering whether he'd react the same way as Clarissa if it was Connor was dying in a hospital bed.

What if Connor was right to be scared about his heart condition? The consultant had attempted to be reassuring – it had been caught early, the operation was routine and not something to get anxious about, there was no reason why Connor shouldn't live a good life with the correct medication etc. Even so, he wondered whether it would be justified (if unethical) to try to get hold of his father's medical records and pass them by Thomas or Nikki for confirmation – not that either of them would be likely to know more than a consultant cardiologist…

Clarissa's desk lay empty for nearly a month after her mother's death. Max had insisted on a complete break and Thomas had been happy to grant the time – indeed, he could hardly complain, since Clarissa had always been one of the first employees in each morning and was frequently the last to leave. He'd found a temp, but the man had only lasted a couple of days before coming down with a virus, so Jack had to muddle on alone.

The Lyell felt forlorn within a few days of her absence. Jack tried to carry on as normal but couldn't get over the strange sensation of lifting his head to make some observation or ask a question, only to be faced by that empty space. Nikki and Thomas by necessity were often absent for hours, either in the cutting room or giving testimony at court, and Jack himself could spend days investigating a crime scene, but Clarissa was the one constant in the office – the glue that held them together.

Thomas commented on it one day, as he was passing through. "Feels odd, doesn't it? I'll be glad when she's back."

"Mmm." Jack nodded absently, as he frowned at some photographs, trying to spot something that felt wrong about the apparent suicide he had just attended.

Thomas paused. "Coffee? I mean, a proper one?"

As Jack looked up in surprise, he smiled. "You look like you could use it. And a break. Want to go and find a decent one for a change?"

"Yeah, sure." He locked the computer and grabbed his jacket, a little surprised by the invitation.

Thomas had grown on him over the years, but he was still very much the boss. In general, the older man got on well with Nikki these days and it appeared that he'd also been quietly befriending Clarissa, judging by her reports of occasionally going for a drink with her fellow 'adult'. He hadn't made the same effort with Jack, though. Jack respected and liked him, although not quite as much as Leo, but this friendly approach surprised him. He wondered, uneasily, whether Thomas wanted to discuss Nikki. He didn't think his recent behavior could have caused any concern. Or maybe Nikki had finally made a decision about her future and had discussed it with Thomas in confidence? But surely, she'd tell him first if she was planning to leave?

There was a café not far from the Lyell – they were all frequent morning customers, taking it in turns to bring in takeaway cups for the team. It wasn't usual to linger there, but Thomas appeared to be in no hurry, purchasing their coffees and sitting down at a table by the window.

"Thanks for this." Jack blew the steam from his espresso and took a grateful sip. "There's something off about that Corlett case."

"Yes, I thought there might be." Thomas frowned in thought; Nikki was out at court all day, so he had done the autopsy. "Textbook suicide, but it doesn't feel right, does it? You get a gut feeling for these. Can't really describe it…"

Jack nodded his understanding – he knew exactly what Thomas meant. These were the cases that frustrated Thomas and Nikki the most; they had to be absolutely confident with the evidence they presented to the coroner, and neither of them enjoyed having to do that when there was just a niggle of doubt at the back of their minds. Jack could sympathize, but the onus was not on him, so he couldn't fully appreciate the stress. "When do you need to let them know by?"

His boss sighed. "I can hold them off until the morning if you think it's worth a second look?"

Jack nodded. "Maybe. I'll keep digging." He hesitated. "Is that why you brought me here – for a break and a fresh perspective?"

Thomas hesitated. "Not entirely…although it may help. No Nikki to bounce ideas off – or Clarissa." He smiled. "Whatever would you - we - do without them, eh?"

Jack gave him a sharp look over the rim of his cup, but the pathologist's eyes were kind rather than speculative. Clarissa had suggested that Thomas was not blind to Jack's feelings about Nikki, but even if that was the case, it didn't seem that he intended to make an issue out of them.

"Good question. You've not…heard anything about Nikki's plans?"

Thomas looked genuinely startled and a little alarmed. "No, nothing. Why – do you think she has plans?"

"No, no!" He shook his head quickly. "At least, nothing that she's said to me. It's just that…don't you think it's a little odd? They've been together for years."

"There's more than one type of relationship though, isn't there?" Thomas' voice was quiet, and his eyes seemed to look into the distance for a moment. "We don't all marry and live happily ever after. Maybe the distance suits them, in a strange way."

It wouldn't suit me, was the obvious response to this, but from the wry look on Thomas' face, Jack sensed he didn't need to voice his feelings. Oh yes, Thomas knew perfectly well…

"Anyway, no, it's not Nikki I'm concerned about right now. It's you."

Jack's head shot up at this. "I know I've been on leave quite a bit lately…"

Thomas brushed this aside. "Don't worry about it. I know it's a worry when a parent is ill, and I know you can't plan far ahead right now. Just take the time you need…but if you think it'll be easier to take a couple of weeks' away after his operation, let me know. I can get another temp in from the agency, since it looks like the current one won't be coming back."

"Thanks – I appreciate that." He dropped his gaze back to his coffee, a little morosely.

"I've been there myself," Thomas offered, a little hesitantly. "I might know more about what you're going through than you might think." He paused. "I know you talk to Nikki and Clarissa about these things – I've heard you, but you can come to me, you know."

There was something slightly plaintive in his voice – a note that Jack had never heard before. He knew that Thomas had tried hard, since his rocky early days, to be on good terms with his staff. His professional relationships with Nikki had been difficult at times, but they'd always made up, and in fact there was a degree of gentle affection between the two pathologists – a shared sense of humour and a mutual respect. Nikki had repeated to Jack the comment that Thomas had once made to her about always being "liked" – they'd both been a little unsure about the veracity of that statement at first, but he didn't dispute it now. Thomas could be outspoken, he could be socially awkward and occasionally rather blunt, but he was essentially likeable. It wasn't that Jack didn't trust him – he just didn't really count him as a confidante.

Thomas went on. "I lost my father twelve years' ago. Liver cancer. My parents divorced years before, and Mum had moved abroad, so I was the one who had to support him." He smiled. "Only child syndrome."

Jack nodded his understanding – in his case, it was more like 'might as well be the only child' syndrome. "Um, did he make it?"

Thomas shook his head. "Diagnosis came a bit too late. I was a new dad myself and in a demanding job, and just maybe if I hadn't been so caught up with my own concerns…" He stopped, shaking his head. "But it's a tricky diagnosis and not very likely I'd have noticed any sooner than his own doctors. He…didn't have a great death."

"I'm sorry." He wasn't sure what else to say. He was learning more about Thomas in this short conversation than he'd found out in years.

"In a way, I had a similar dilemma to Clarissa. Not regarding the consent situation, of course. Dad was as sharp as a tack, always had been. And he wanted to live – he really did. But…it was hard knowing the realities of the treatment - how tough it would be. And he'd ask me." He shook his head, his eyes distant again. "He knew that I knew how well it was going, whether or not he was going to make it. Whether – and when - he would need to think about giving up."

"That must have been tough."

"Yes…not an easy thing to do… It's a strange feeling, isn't it?" he added, suddenly. "All our childhoods, our fathers are the ones we emulate, for better or for worse. I admired my dad. He was a diplomat - did you know? I was born in Pakistan, but we moved around a lot, and he always knew how to fit in to any situation. They – fathers – they always seem to know everything when you're a child, don't they? And then you grow up, and suddenly they're not infallible. Suddenly you… you know more about a situation than they do. They're relying on you. And…that's not easy, is it?" He looked at Jack very directly, with compassion in his eyes.

Jack suddenly wished he'd confided in Thomas Chamberlain a very long time ago. It was strangely comforting talking to another man – he'd been used to sounding off about his problems to Clarissa or Nikki for years, but he sensed that Thomas might be right to suggest that his own experience was closer to Jack's. Thomas was non-judgmental and unemotional and – fundamentally – kind. Almost brotherly.

He sighed, lifting his shoulders slightly. "I don't know what to say to him. The consultant says it's a straightforward operation, but he seems so scared…"

"It is," Thomas asserted, confidently. "In the vast majority of cases, the patient comes through with no problems. She's a good consultant too – excellent reputation. But…all you can do is be honest. I found that was the best thing with Dad. Because if yours is anything like mine, he'll know if you're hiding something. It's perfectly natural for him to feel fragile and scared – a heart condition can puncture your confidence. Just keep supporting him, the only way you know how. And that means taking off whatever time you need. I trust you to make it up when you can – or document it as time off if necessary."

Jack relaxed a little. "Thanks. That helps a lot. I had wanted to ask about the op, but I didn't like to."

"That's OK. I overheard you telling Clarissa what the operation was, and thought I'd check out the consultant – just in passing, you know," he added, a little lamely.

Jack smiled. It was kind-of sweet – and very likeable – of Thomas to investigate something on behalf of a colleague, just in case he was asked to. However, he was beginning to appreciate that it was a very 'Thomas' trait. The pathologist loved to know things – he was very fact-focused. A bit of a geek…but then, weren't they all at the Lyell? Maybe that was why they worked together so well. A little family of geeks.

"Um, why are you…" he paused, not sure how to put it politely. "I mean, I appreciate the advice, but I'm wondering…what made you decide to talk now?"

Thomas gulped the remains of his coffee. "Because of Clarissa. I feel that I let her down."

"Why on earth would you think that?"

His boss shrugged. "I could see that she was struggling, but I kept my distance. I reasoned that you and Nikki know her much better than I do, and she wouldn't need me to weigh in too. That may have been a mistake… It was a relief when she decided to take time off, because I'm sure she would have regretted not being with her mother." He paused, then added quietly. "To tell the truth, I'm a little worried that she might not want to come back."

Jack bit his lip, concerned. "Has she said anything?"

"No…it's just my spidey-sense." He grinned at Jack's confusion. "You know – my intuition. Bit like the Corlett case."

Jack frowned and drained his mug. "I'd better get back to that. Thanks for this, though – I needed the break. And I appreciate the advice about Dad."

"Not at all." Thomas patted his shoulder as they got up. "As I said, if you need some time, don't hesitate. I don't want to make the same mistake with you, and I certainly don't want you to get stressed or feel that you need to leave. We need you at the Lyell. I need you – and I'm pretty damn sure Nikki does."

He was passing ahead of Jack out of the café, so his face was hidden, but there was just a hint of dry humour in the last few words.

"I'm sure Clarissa will be fine, by the way," Jack commented as they strolled back to the Lyell. "If she had any idea of leaving, she'd tell me first."

She didn't tell him first.

That was a bit of a gut-punch to Jack. He'd always known what was happening in Clarissa's life. He'd been the first to know about Max, for example. They'd spent hours talking, over cheap wine and crappy snacks, about her secret hopes and fears when the gangly, awkward IT geek had walked into her life and steadfastly refused to be put off by her attitude. Clarissa had built a protective wall around her feelings – of necessity when she faced bullying and discrimination every day. It had taken a while for Max to penetrate it, but Jack had to admit that his persistence had been worth it. He'd always viewed the formidable Mullery-Thorndyke partnership as the real deal – modelling his own romantic relationships on theirs.

He'd talked Clarissa into coming with him to the Lyell, and it had been one of the best decisions he'd ever made. The thought of having to carry on with her – of having to get used to another lab assistant – appalled him, but he was also deeply hurt not to have known.

He meant to have it out with her when the opportunity arose. There'd be time – they'd have a drink or maybe he'd finally take her to that Michelin-starred restaurant that he'd promised on so many occasions…

But then, quite suddenly, there wasn't any time at all…

Jack stares after the stretcher taking DS Vail into the back of the ambulance, his thoughts scattering.

DI Guyatt's voice seems to come to him from far, far away. "Three generations of the same family… We know Major Sealy's house was broken into… Any evidence that anyone else was in the car with Sealy…"

His arm twitches. His blood seems to be running slow.

"Haven't finished my investigation yet…"

He half-turns from the ambulance. His vision blurs…and then his legs give way.

"Jack? Jack!"

That chemical equation… a nerve agent… Oh, Christ… Oh God, please no… Dad – the operation… Nikki… Nikki… oh, Nikki…

He's aware of faces in masks, the cloudy sky above, behind them. He feels himself being wheeled into an ambulance…and wonders if he'll ever see the sky again…