He smiled. ‘There’s no staff restriction on chocolate – that’s just for the clients, y’know, to keep you healthy. So, technically this is contraband. But I won’t tell if you won’t.’

Tell. There it was: her chance again. Tell him, she thought, as she looked at the chocolate bar and up into his kind eyes. But she’d probably imagined it, hadn’t she? It had been a bit of plastic fluttering in the wind, a bird, an old bit of paper, a trick of the eye.

Not a face.

Chapter 11

‘The white-crowned sparrow, when it is migrating and has to be in flight constantly, can go pretty much completely without sleep. Nifty little trick, right? But, get this, the bird does this with nearly no side effects.’

Weirdly for a lecturer specializing in sleep, it didn’t look as if he got much: he was twitchy and hollow-eyed. He stopped here to let his words sink in, smoothing back his threadbare hair.

Thea had been attending these Sleep School lectures for a few days now. Sometimes, she realized during those lectures, she was so busy looking thoughtful and attentive that she forgot to listen to what the lecturer was actually saying. She quickly corrected that now and tuned back into him.

‘Imagine you are that bird, hmm?’ the lecturer continued. Thea wrote down notes; there might be some sort of test on all of this and she didn’t like to fail at things. Failing at sleep was enough. ‘Every spring and autumn, tens of thousands of white-crowned sparrows (Zonotrichia leucophrys) migrate the 4,000 kilometres between Alaska and Southern California. They fly day and night with little chance for rest. Imagine it: flapping away constantly, on the move to your winter home, you can’t fall asleep because you’d plummet from the sky and die. You’ve also got to keep an eye out for predators and keep yourself fed. Solution? Stay awake, of course! Scientists are currently trying to understand what is going on in the bird’s brain at that time, especially … and this is the key part … especially as these birds sleep two-thirds less than normal yet, in certain tests conducted, performed no worse than other sparrows on tasks of learning and memory.’

He paused for a moment.

The man a seat away from Thea was drawing a bird in his notebook; it had angry, bloodshot eyes and a coffee cup held between two wings. The speech bubble coming from it said, ‘Caffeine! I need more caffeine!’

‘Imagine it, hmm? Imagine not having to waste all that time asleep … and for it to have absolutely no effect on your physical and mental wellbeing. Well, Morpheus is already imagining that.’