One thing she hadn't counted on was the solitude. No- the loneliness. She's always preferred to call it solitude, even before the disappearance- it took away the hard edges of the feeling that gathered when she'd put a hand up in class too quickly, unable to help it, and seen the glances and giggles as she stuttered on her words, or felt that sickening taint of self-confidence stain everything as she tried to work her way past it by acting bigger, and ended up making it worse. That horrible feeling that she would always be an outcast, different, too clever, not sociable enough. Often, she had believed it, and dreamt of someone who would understand. The disappearance took all time for dreaming away.

Then she had found the Sparticles- Sadiq, a caring best friend and clumsy brother, Tia, the bossy older sister and "mum" to Frankie, Jeffrey and Jordan brothers too, along with Ami- all three of them childish and ridiculous in a way that made her scold them and laugh inside. Frankie and Reese were younger sisters- Frankie loud and boisterous, Reese one to be watched for her occasional outbursts of manipulative behaviour. Holly, who was a sister too, in a way, but sometimes seemed more like a cousin- ever so slightly on the outside. And Liam, who should, like the others, be a brother, but lately had started a feeling of maternal pride in her, and a love deeper than that for the others, apart from possibly Sadiq- the sort of love she might feel for her own child.

And there was Callum too, of course. Who knew what it was that had drawn them together- a love of arguing, perhaps? A need for a challenge, and the thrill of a chase? Whatever it was, it had stayed with her long after they first left him, starting a strange fire inside her that she wasn't sure she could control. It burned, so fiercely that when they met at last at Black Tor mine, they had barely needed to speak- they just knew. She hadn't believed it, that he could feel the same way- why would someone like you love someone like me?- but that kiss had sealed everything, making it complete and whole again, and filling her with security and love that even here, even now, warmed her heart.

She had known, from those first few glorious minutes after they found out about the quantum nexus, that she would have to leave. It was something only she could do- she had explained that to Callum, and he, knowing her as he did, accepted it. She had promised they would meet again, and he had said the same- each knowing, without reason, that it would come true. She couldn't picture her life without him, ever- but there wasn't time for anything like that now, and she had to go.

Sadiq covered his unease and worry by teaching her to drive, badly- the laughter hiding the lingering fear that she wouldn't come back, to be the other head of the Sparticle family, as he needed her to be. They had traded a goat and some solar panels for a rusty car, easy enough to run on waste cooking oil if you knew how to adjust the engine- and Kat did. And then she was leaving, packing what little she had left, taking a map and the long-remembered codes to shut down and secure the nuclear power plants, and she had never imagined it would be this lonely. She only did what she needed to survive- what life was there without her tribe, without Callum?- and ate nothing for days on end, strength and a kind of desperation driving her forward. She curled up at night on the back seat, wrapped her blanket around her, and tried to imagine that she was back in the Spartimobile, the others asleep on their various beanbags and cushions. Or that Callum was with her, stretched out on the floor of the car, their breathing matching and soothing them to sleep. She would wake, gritty-eyed and aching from tense nights of crying in her sleep, of dreaming and then waking up to reality. She tried to avoid thinking of them, and steered clear of other tribes- what could they compare to the one she had grown to love? She wonders when she will finish- and remembers what Callum said. "Forever". In a world like this, promises are never made except when they can be kept, and she needs to hold on to this. For Callum, and Liam, she carries on, so that when she returns, there will be nothing to stop them loving each other.