Kate found herself staring at the screen for several minutes before she realised what she was looking at. It was a police report; French on one side of the split screen, English translation on the other. It was the police report for Sherlock's mother's accident. John watched her face as she read it. 'There are photos in the file minimised at the bottom of the page,' he said quietly. 'I didn't know if you'd want to...'

'I'll look at them,' Kate said.

It made grim reading, John knew. The blessing was that both he and Kate were used to reading such reports - both from their day jobs in medicine and from their work with Sherlock. The car that Adrienne Holmes had been driving had been found at the bottom of a ravine. The mountain road had gone round a sharp left hand bend; Adrienne's car had gone straight on, crashing through the wooden barrier and ended up at the bottom of a ravine. Another driver had noticed the debris on the road from the fence, and raised the alarm some twenty minutes later, but by the time that the emergency services had got there, all that was left was a charred and smouldering wreck of twisted metal.

The photos of the wreck were - disturbing, John knew.

'How do they know it was her?' Kate asked.

'Dental records initially, then DNA matching - Sherlock's father insisted on that.'

'Wait - why?'

'You mean why did he want proof that it was really her ? I assumed that he just wanted conformation. You think that he suspected that she could have faked her death?'

'It just seems an odd thing to do,' Kate said. 'I mean, the car was identified as being the one that she hired, the dental records matched, why go through DNA matching? Whose DNA did they use by the way?'

'Mycroft's,' John said quietly, wondering why he was only now beginning to consider the impact that all of this must have had on Mycroft Holmes. He would have been, what, twenty two at the time? Freshly out of University, only a few weeks into his new job in a government department. What sort of impact would his mothers death have had on him at such a time?

'Why not use Sherlock's DNA?' Kate asked. 'Why use Mycroft's?' John saw what she was doing, or was trying to do - she was asking the questions, all of the questions, just as Sherlock would of, had he been here.

'They didn't want him to know the grizzly details,' John said. 'They didn't even tell him that his mother was dead until six days after she died, did you know that? His father sent Mycroft up to get him for an exeat weekend. He was due to come home anyway, but when he got called in to his Housemaster's study at lunchtime, instead of the chauffeur turning up at five to pick him up, that was the first time that he would have known that something was wrong.'

'Christ,' Kate muttered, 'No wonder he coped with it so badly.'

'It gets worse,' John told her. 'The funeral was on the following Tuesday; so they told him that his mother was dead, and four days later he was watching her coffin being lowered into the ground. Not exactly a lot of time to come to terms with what had happened before being asked to face the gritty reality of her death.'

'What does Mycroft say about it?'

John's face twisted slightly, as if he was unsure what to make of Mycroft's answer. 'He said that he was trying to protect Sherlock. He knew that there was a risk that Sherlock would have a melt-down, that if he did that at the funeral then his father would be - angry, that the consequences of that anger would be severe. He wanted to minimise Sherlock's time at home, and to make sure that he could be there with him.'

'So he was trying to protect him.'

'Apparently so.'

'Do we have any reason to doubt him?'

'No, but there's one thing else, Kate. They packed Sherlock back off to school the day two days after the funeral. And that was Mycroft's idea, again. He said that his father was virtually incandescent with anger. He wouldn't speak at the funeral, Mycroft did that, but by the sound of it it was a very formulaic service - a bible reading, a poem, a brief biography, but little more. Mycroft wanted to get Sherlock away from that - thought that he'd be safer at school than at home.'

'Why was his father so angry?' Kate asked.

'I don't know,' John said. 'Another mystery for us to solve. Mycroft said that his parents often argued, but he wasn't at home when his mother left for France this time, so he has no idea what the dynamics were.'

'Did Mycroft get on with his mother?'

'He admired her, I think. But I'm not convinced that she ever confided in him. What is interesting is that he had no idea what her visits to France entailed. He thought that she went to visit relatives when her relationship with his father got too fraught. His father told him that she had a string of affairs, but I could find no evidence of that.'

'Have you told Mycroft? About the clinic there?'

'Yes. He was - surprised, but not shocked. Said that his mother often took to her room for days at a time, was 'emotional', I think that was how he described it. He found it embarrassing, especially if he had friends from University to stay.'

'So -' Kate broke off, and rubbed at the side of her face in frustration. 'Actually I have no idea where I go from here. How do you do it, John? I've got a thousands questions running through my head, and no idea how to take any of them forward.'

John smiled at her. 'It takes practice,' he said. 'Sherlock used to say that you followed one track as far as you could - some of them are dead ends, some of them peter out and you have to put them on a back-burner while you wait for the evidence to come in, some lead to the centre of the labyrinth. You pick a thread, and just keep digging.'

'I do not for one second believe that Sherlock would have mixed that many metaphors,' Kate said solemnly.

'No, you're right,' John admitted. 'Most of those are mine. Sherlock made it sound a lot more complicated, and used a lot more long words; that was the summarised version.'

'So which thread do I follow now?'

'The original one. Always go back to the beginning. So we've got Adrienne leaving the psychiatric hospital, getting in a car and ending up at the bottom of the cliff. What questions does that bring up?'

'Why did she leave the clinic; where was she going; how did she end up at the bottom of the cliff; why did Sherlock's father think that she might have tried to fake her own death; why was he angry with her.'

They were both silent for several minutes, considering.

'When you say it all like that, isn't there a possible link?' Kate said slowly. 'I might be miles wide of the mark, but what if she was trying to get away from her husband. That would tie in all in wouldn't it?'

'Perhaps, John said. 'The thought had crossed my mind too. The housekeeper who worked for the family at that time couldn't tell me much, other than that Adrienne and Richard weren't getting on well in the weeks before she went away - lots of raised voices, lots of arguments. Then she took to her room and a week later left for the clinic. I'm trying to track down a woman called Francois Marchand, who the housekeeper tells me was a fairly frequent visitor to the house, and often accompanied Adrienne on her trips abroad.'

'A companion - or a keeper?' Kate asked, interested. 'It's all a bit Victorian, isn't it?'

John laughed. 'A childhood friend, the housekeeper thought. Certainly someone that Adrienne was fond of.'

'Have you asked Sherlock about her?'

'Not yet. I'm trying to keep him out of it as much as I can. Mycroft remembers her coming to stay occasionally during his childhood, then a long gap, then she reappears after he went to University. I wondered if she got married in the interim, and her husband wasn't approved of perhaps, its just a theory.'

'Is Mycroft helping to track her down?'

'He's got people onto it, yes. It would be simple enough via birth records and so on, but my French is rudimentary to say the least - he's got people who can do the job far more easily.'

'Aren't there letters or anything from her among Sherlock's mothers things, something to give you a clue?'

'Nothing, thats the odd thing. There are lots of old invoices, official letters,family papers, but nothing personal relating to Adrienne at all.'

'You think Richard Holmes just had a big bonfire and burnt it all?'

'Perhaps. I don't know. Mycroft said he went back to work the day after he took Sherlock back to school, his father hardly even spoke of their mother after that.'

'So another dead end,' Kate said. ' For now anyway. So what's the next thread?'

'Now you're getting the hand of it,' John grinned. 'The next thread is the accident itself. What happened and why.'

'So,' Kate said. 'She could have swerved to avoid someone?'

'No evidence of any other cars involved,' John said, 'The only debris was from her car. It was a narrow car. If another one was involved, then I'm reliably informed it would either have scraped the barrier, or the rock on the inside of the curve. There's no evidence of either.'

'She could have swerved to avoid something then - an animal perhaps?'

'No skid marks,' John said slowly, watching Kate's face. 'I checked and double checked. Nothing, and the photos of the scene corroborate that.'

'But she must have skidded,' Kate said. 'When she knew that she was going to hit the barrier she would have -'

John shook his head. 'She didnt brake, Kate.'

'But that means -' Kate broke off.

'It was a left hand bend,' John told her. 'She was driving on the right side of the road, the outside. The road went round a corner and she didn't. She hit the barrier head on and she didn't brake.'

'What if she blacked out?' Kate said desperately. 'She was on a whole load of psychotropic drugs, they could have dropped her blood pressure, made her black out.'

'She would have taken her foot off the accelerator,' John said gently. 'You know that. People lose their muscle tone when they black out, she would have slowed down and come to a stop. I'm told that she must have hit the barrier at a minimum of seventy miles and hour to go through it the way that she did.'

'A fit?' Kate asked, desperately not wanting to think about the alternative.

John shook his head slightly. 'You're grasping at straws, Kate. There's only one possible explanation for her accident, if we can still call it that, and we both know it.'

Kate closed her eyes tight for a moment, trying to focus on the seat beneath her, on the weight of her own body sitting in it, on the rocking movement of the train, on her breath in and out. It was an old technique that she'd learnt years ago during her own time in hospital. A relaxation and anchoring technique that she still used to remind herself of who she was and where she was, of her own place in the world when her thoughts threatened to splinter and become unreal.

'So you're saying that she killed herself,' she said quietly, focusing on the table, not wanting to look at John.

'Looks like it,' John said quietly. 'That's what I think, and that's what Lestrade thinks, given the evidence. He says that there is no other possible explanation, and I have to say that I agree. I think that Adrienne Holmes killed herself. Which leaves two questions; why did she do it, and how on earth are we going to tell Sherlock?'