that a joke? It was difficult to tell with Edward, but the possibility intrigued Charlotte. She could see Lucy and Isaac out of the corner of her eye, settling themselves down on the sofa with their drinks. They’d be at least another five minutes, and hadn’t Paula always said that Charlotte only needed five minutes to get anyone to open up?
‘What’s it for? If you don’t mind my asking?’
‘You can use it for anything. I’m thinking of DNA sequencing.’ The way he brushed off the question almost made her believe that everyone had a model of a DNA sequence somewhere in their office.
‘Ah. Right. Anyone in particular?’
‘Mine, actually. Just a snippet of it, of course. But don’t you think there’s something rather interesting about actually being able to look at something that’s the very basis of your own make-up?’
‘I’d never really thought about it.’ Now he mentioned it, there was. There was an obscure symmetry about the concept that made her smile, even if she didn’t properly understand it.
‘You should. It would be interesting for Isaac...’ He narrowed his eyes. ‘Perhaps when he’s a bit older.’
‘Yes, I think so. Is that all?’ She should go now. She’d managed to stem her tears for the moment, but who knew how long that particular dam was going to hold? Hopefully until after Isaac was safely tucked up in bed.
‘Are you going home? I’m going your way. I’ll give you a lift. The buses are horrible at this time of day—’ He broke off, as if he’d let something slip that he shouldn’t.
How did he know she took the bus home? And how did he know which way she went? Charlotte stared at him.
‘I’ve seen you waiting at the two-three-nine bus stop. And the two-three-nine goes almost directly along my route home. Of course you could be catching the number thirteen, but most people who do that walk down to the Oxford Circus stop, so they can get a seat—’ He broke off again, obviously wondering whether that was too much information.
‘Right. Next time I want to know which bus to take, I’ll know who to ask.’ She grinned at him. ‘But it’s okay, really. You must still have work to do and we’ll be going in a minute.’
He shrugged. ‘I was operating at six this morning, I should have been gone hours ago. And... You look tired.’
Perhaps Edward noticed more than everyone thought.
There was no perhaps about it. He clearly did. Somewhere inside a smile formed at the thought that some of those things were connected with her.
‘We...we can’t. Isaac needs a proper car seat...’ It was a pity. The buses were always packed on a Friday evening and she could have done with a ride home.
‘No problem. I have one fitted in my car.’
Something told Charlotte that Edward had worked all of this through before he’d even made the offer. The complex equation balanced two shopping bags, one child and an indeterminate number of full buses, crawling through the traffic, against one child seat, a comfortable car and a lift home. He probably already knew what she was about to say.
She smiled, wondering whether he’d factored that in or not. ‘Okay. If it’s no trouble. Thanks.’
EDWARD GAVE NO explanation for the brand-new child’s car seat when he opened the back door of his sleek dark blue car and waved Isaac inside. Perhaps the girls at work were right. Perhaps he did have a woman somewhere. A woman with a child. So much for Paula’s assertions that it couldn’t hurt to try to breach Edward’s reserve.
All the same, there was nothing wrong with taking a lift from him, and Charlotte couldn’t deny that this was a great deal nicer than the bus. Not having to continually grab at her bags to get them out of the way of someone else’s feet. Isaac safely strapped in behind her, with Stinky on his lap. Leather seats. The quiet strains of music floating at her from four different directions. She began to relax.
‘It would be more convenient for you to drive to work.’
As they passed Regent’s Park Edward’s customary forthrightness broke the silence.
‘Yeah. More expensive, too.’ She grinned at him. ‘Congestion charge, parking costs.’
He nodded. ‘I thought you were going to say you liked the bus.’
‘It’s not so bad. You meet a lot of interesting people on buses.’
‘So it’s a social experiment, then?’
Maybe for Edward. It was a matter of necessity for Charlotte. ‘You could call it that. We like it on the top deck, don’t we, Isaac?’
‘Yeah. You can see into people’s windows,’ Isaac piped up from the back seat.
‘Can you?’ Edward paused for thought. ‘What do you see?’
‘Christmas trees.’
‘In July?’
‘No, at Christmas.’ Isaac’s voice took on the tone of patient explanation that he sometimes used with adults. ‘We counted how many Christmas trees we could see on the way home.’
‘So you’re a mathematician. Is that why you’re called Isaac? After Isaac Newton?’
Isaac seemed to have succeeded where the combined talents of the Hunter Clinic had failed. That was definitely a joke, even if Isaac didn’t appear to understand it.
‘Who?’
Charlotte rolled her eyes. ‘He’s five, Edward.’
He nodded. ‘So you’re keeping Newton for later.’ He made it sound like leaving the best chocolate in the box until last. He raised his voice, speaking to Isaac again. ‘So how many Christmas trees did you count?’
‘A million.’
‘Really? You live on the moon?’ Edward’s lips twitched and Isaac cackled with laughter. Although neither seemed to be quite on the same intellectual wavelength, they clearly shared the same sense of humour.
‘Noooo. Kentish Town.’
‘That explains it, then. Are you sure you didn’t count any of them twice?’
Isaac shrugged. ‘Maybe. It might have been a hundred.’
It seemed so natural to laugh with them. The obvious thing to do. ‘It was three hundred and forty-nine, wasn’t it, Isaac?’
‘That’s right. Three hundred and forty-nine.’
Edward nodded. ‘Impressive. That’s a prime number, you know.’
‘What’s a prime number?’
Edward shot a helpless glance at Charlotte and she shrugged. All of a sudden
