Lyn began the audiobook after briefing Sam on the story so far. It was a ludicrous tale but Sam enjoyed her enthusiasm for the drama. They both fell silent as Lyn turned on to the M25 to head for the M11. Sam did his best to keep up with the story but tuned it out after a few minutes. Instead he stared at the road ahead as the little car at up the miles, and Lyn seemed to get lost in the tale they listened to.

"T

en quid for your thoughts," said Sam after twenty minutes of silent driving.

"Huh?" said Lyn.

"Where are you?"

"Ten quid? What happened to 'a penny for your thoughts'?"

"Inflation."

Lyn nodded sagely. "Of course. How silly of me."

"Is the story so good you're going to ignore me until we get to Cambridge?"

"Oh no. Sorry, I was miles away."

"Thinking about today?"

"I was. About the interview at the police station."

"Oh yeah," said Sam, and Lyn could hear the defensive note creep into his voice.

"What did they ask you?" she said. "It sounds like it bothered you."

"It was what they implied I didn't like."

"Tell me."

"They asked about my work, but you know I can only tell them so much."

Lyn smiled into the darkness. "Classified!"

"Yeah."

"Even to the police?"

"Afraid so. National security trumps a local investigation."

"So would I be right in guessing they didn't like how you seemed to be hiding something."

"I guess so. I gave them contact details of my superiors so they can take it up with them if they feel like it, but I couldn't say any more than I did."

"So what could you say to them."

"Well I told them I worked with explosives and I was taking part in a genetic study and that's why I was there. It's ok to tell them what I was doing there, isn't it?"

Lyn dismissed his concern with a wave. "Of course. Everything we do is public record. That's the point. Obviously we keep our patient's details hidden, but the results of the research are public. I'll publish you one day under the name 'Mr A', and everyone will assume that your real name starts with anything but the letter 'A'. But what did they say that you didn't like?"

"They were making insinuations about the fact I know about explosives, I've been to your lab before and that I wasn't there when the explosion happened."

"You were getting coffee with me!"

"I know. What a coincidence."

"But what about the guy you caught? That has to count for something."

"Maybe. I don't think they were serious. I think they just wanted to wind me up because I claimed confidentiality."

"That's not a very professional attitude."

"Yeah..." he hesitated, "But I understand it. I'm a professional but I'd be lying if I said no-one had ever wound me up before."

Lyn looked at him sideways.

"You did something at work you shouldn't have?"

"Something like that. It doesn't matter. How was your interview?"

"Fine, mostly. Or at least it started out fine."

"What do you mean 'started out'?"

"I had to explain the work we do, but you know I do that a hundred times a day, it seems, so that was no hardship. But then they stopped asking me about the facts of what we do at Zoitech and they began asking if we were playing God, and things like that."

"Why did they do that?"

"I don't know. Wait, yes I do. It was after someone called the detective away and someone else came back with him. Detective Allen."

"Which one?"

"The new one. Her name was Detective Allen, and she had this big folder full of notes, and they started asking questions about that."

"The playing God questions?"

"Yeah. But they were weird."

"How so?"

"Because they were so specific about the research we do. They stopped asking about the explosion, or for my witness statement."

"Like what?"

"Like, they asked me what a haplotype is. I remember that because it's not a word you hear much outside my field."

"I've never heard of it."

"Why would you have?"

"So what is it?"

"It's a group of genes that can be inherited from a parent."

"What's that got to do with the explosion?"

"Nothing. That's my point."

"So where were they getting the questions from?"

"I don't know. I can't imagine any of the staff would have given them information like that. It's just not relevant."

Sam thought for a moment, then said, "It might be relevant to someone."

"Who?"

"The guy that blew up the lab. They guy they arrested."

It was the only thing that made sense, Lyn thought, but pushed Sam with another question so he could do her thinking out loud for her.

"Why?"

"He was trying to steal some dna. Maybe they asked him why and he told them it was something to do with hablotypes."

"Haplotypes," said Lyn automatically. "I wish I knew why he was trying to steal it. No-one needs to steal it, it's all on line."

"So the question is, what can he do with the real dna that he can't do with the information on a website."

Sam laughed. "So what? They are cloning you?"

"Be serious. We are still years away from something like that. I don't know, but it must be something that needs a lab. But where would his lab be?"

"He isn't necessarily the guy doing the work. He was probably just hired to steal it."

"He knew what he was doing though," Lyn pointed out.

"Ok, ok," said Sam, waving his hands to clear the air. "So this guy steals your dna because he needs it for something. Your lab is all about open access and he must have known that, and yet he tried to steal it anyway. Why bother?"

"I don't know. Because...because what he needs it for isn't legal?"

"So what is illegal in genetic research?"

Lyn shifted her grip on the steering wheel and began ticking off her fingers as she counted.

"Ok, one, unlicenced stem cell research. Two, human cloning. Three, experimentation of human chimeras. Four, human transgenics, and five, use of genetic testing in insurance."

"Do you think this is an insurance scam?"

Lyn shook her head. That's more ridiculous than the cloning idea."

"And you said cloning is still years away anyway?"

"Right. But it's almost certainly going to be illegal under most circumstances when it happens."

"I've heard of stem cells. Aren't they something to do with embryos."

"Sort of. Stem cells are like blanks for the body. They can grow into any cell the body needs, like muscle, or bone, or blood, or an organ. They have the potential to be anything."

"Isn't there something controversial about them?"

"You're thinking of embryonic stem cells. That's when an egg is fertilised in vitro, in a lab, and an embryo develops. But at very early age, just a few days, the embryo is still a collection of potential cells. They haven't yet started forming into bones, or brains or hands. They're pre-human clusters of cells."

"But that's the controversy isn't it?"

"Yes, some people think even at that stage they are human beings with all the rights that come with that label."

"But you don't?"

"No. Not at that stage. I understand the concerns people have but the cells we work with are only a collection of stem cells. If even one cell of heart of brain hasn't yet formed then how can it be human. It's not more human than an egg." She glanced at him, fearing judgement. "Do you think I'm a heartless monster because some of what we do involves those cells?"

"I'm in no position to judge anyone about something I don't understand, Lyn. And if we started worrying about the things we do in our profession careers you would be asking me to get out the car."

"I'm sure that's not true."

"Anyway, you said unlicensed work is illegal, so what you do must be ok."

"That's right. But it wasn't stem cells that were stolen, so it can't be anything to do with that."

Sam knuckled an eyeball as he tried to keep up.

"So it's not stem cells, it's not insurance fraud, and it's not cloning. So what about a chimera? Is that like a hybrid?"

"They're different."

"Of course they are."

"A hybrid is a mix of genetic material from two different species which is caused by sexual reproduction, like a mule, or a liger."

"A what?"

"Part Lion, part Tiger."

"That's not a real thing!"

"Sure it is. Go to a zoo sometime. The genetic mix can produce unexpected results. Infertility is common, but the Liger, for example, can grow up to five hundred and forty kilograms. A typical lion might be two hundred and thirty kilograms and a tiger less than two hundred and seventy. You can't always predict the outcome when you mix genes like that. The interactions are too complicated."

"And a Chimera?"

"That's an organism with genetically distinct cells. Some happen naturally. In humans you might have someone with two different blood types, for example.

"They sound pretty similar."

"I guess so, but geneticists have strict definitions to tell them apart. The cells of a hybrid creature are derived from both parent species but a chimera contains two distinct cell lines."

"And what was the other one? Transgenetic?"

"Transgenic. That's when you modify the dna of one creature with the dna of another. Like those mice that glow in the dark."

"Are you winding me up now?"

"No! This is all real science. It's out there now."

"Why would someone make a mouse that can glow?"

"To see if they can, of course! Although strictly speaking they were florescent under UV light. The aim wasn't to make sure no-one lost their pet mouse again, it was to see if we could take the qualities of one organism and translate them to another. A green mouse is just a highly visible proof-of concept. They did it by taking genes from a jellyfish, but in theory, if we can isolate the right parts of a genome, we could develop traits and qualities in one species to benefit another."

"I don't even know where to begin trying to understand how that is possible."

"Well, we've had good results with using a modified HIV virus as a delivery vector, and-"

"Ok, ok, ok. But getting back to the subject at hand, what does this have to do with the questions the cops asked you. What illegal thing can that guy have wanted to do with your dna?"

Lyn gave a helpless shrug. "Nothing. There's nothing special about it, so I can't think of anything that my dna could be used for that no one else's can. We're all human, after all."

"They didn't ask you anything else?"

"They asked something about Eve."

"From the Bible?"

"The genetic Eve. I thought they were going to ask about the Bible or religion or something like that because it's not uncommon for us to have to deal with opposition like that. You know, playing god, the power of life and death, that sort of thing.

"Yeah, I know the sort of thing. So who is the genetic Eve?"

"She's no-one. She died hundreds of thousands of years ago. She's the person we find if we trace back in time the dna of every living person. Every woman I mean. You can only trace this dna through the female line."

"So any woman alive today is descended from this one person?"

"Partially. Dna fragments over time so there is no single person alive today you could call a descendent. So like I said, she's no-one."

"Sounds more like she is a bit of everyone," said Sam.

"Huh," said Lyn. I guess she is."

"What's that noise?" Sam asked, suddenly distracted. He twisted to look at the back seat and saw a glow emanating from Lyn's handbag.

"Oh, my phone! Can you reach it?"

Sam didn't need to stretch far in the small car. He pulled out the phone.

"Who is it?" said Lyn.

"Don't know. It's a withheld number."

"Can you answer it for me?"

Sam swiped a finger across the screen and the phone died.

"Who is it," said Lyn, concentrating on the traffic.

"I don't know. I think your battery just gave up."

"Agghhh," said Lyn. "I forgot to charge it back at the office. I've been using it all day!"

"Do you think it was the office?" said Sam.

Lyn glanced at the dashboard clock.

"Not at this time, and not from a witheld number. It doesn't matter, If they leave a message I can pick it up later."

Sam dropped the phone back into the bag, and they continued their journey north.