She sighed. Even in their eternal two-day bubble world, the same cars, the same pedestrians, the same yellow cabs passing the end of their little backstreet at the same time every day … even in this world frozen into two endlessly looped days, time was passing for them. She’d noticed it … and wondered if Sal and Liam had noticed it too, not that either had said anything to her.

We’re all ageing.

She could feel it very subtly. It didn’t show, not yet, but she could feel it. Maddy had studied her face in the mirror of their latrine. Stared at her face wondering if she might detect the first faint signs of hairline creases in her skin. But … so far, to her relief, no.

As for Sal, she was perhaps a shade taller. After all, measuring the time they’d been in the archway together in a normal way, they must have been living there now for — what? — five months?

Was it as long as that already?

Five months, and like any thirteen-year-old Sal still had a few more inches of growth left in her. Perhaps, being the youngest of them, the corrosive ageing effect of the archway’s displacement field would be kindest of all on her — take the longest to make itself felt.

But Liam … poor, poor Liam. She could see the signs of accelerated ageing in his face even if he hadn’t noticed it yet. Or perhaps he chose not to. His jaw and cheeks were less rounded now, longer and leaner. And around his eyes — eyes that always seemed to be wide like saucers with genuine awe at something, or pinched tight mid-laughter, laughing at the oddness of this bizarre life they were living — those eyes … eyes that had seen more than any one person should ever hope to see. Around them, in his soft pale skin, Maddy could see the first hairline traces of age. The very same hairlines that would one day be the folds of wrinkled skin on Foster’s ancient face.