‘And in the event you can’t get back to the blue light,’ Malcolm says, wide-eyed at the lunacy of these two, ‘we’ll give it five minutes then pull you both back on the ropes.’

‘Ropes, got it,’ Harry says, rising up so he can hunker down again. ‘Water, doctor, blue light, rope, tea and cake . . . RIB.’

‘Five minutes isn’t very long so you’ll have to move fast,’ Malcolm says. ‘You’ll land at the GPS signal recorded from the distress signal when the boat capsized but you’ll have to search visually.’

The last two hours have been frantic, with Malcolm and Konrad rushing through the device to get the equipment needed while Roland strutted and blustered about.

A high-sided rigid inflatable boat. Wetsuits. Life jackets. Rope and reel. Water goggles. Gloves. And Ben being carried gently to his bed by Harry and Safa and the threat made that everyone here will die horrible, painful deaths should he not be alive and in the same bed when they get back.

‘This is madness,’ Roland mutters, tapping at the screen of the tablet. ‘Complete madness. Powering up.’ Red lights blink on the black boxes and the room fills with a low thrumming sound. ‘Calibrating . . .’ he says and waits. A few seconds and he starts tapping his finger on the side of the screen, humming a tune.

‘Water, doctor, aboard, light, get back,’ Harry says. ‘You want this engine on now?’

‘Oh, good idea,’ Malcolm says, blinking in surprise. ‘Didn’t think of that . . . you know how to do it?’

‘Pull cord?’ Harry says, staring at the big engine.

‘Er, no,’ Malcolm says carefully, ‘we don’t have pull cords these days . . . press that button.’

‘This one?’ Harry jabs the button. The engine starts instantly, coughing thick black smoke into the room before rising in pitch to a dull scream that only gets louder when Harry test twists the grip on the rudder stick.

Roland coughs pointedly. ‘Ready,’ he says, and rolls his eyes when no one hears him. ‘I SAID IT’S READY.’ He waves.

Harry nods, giving him a thumbs up. Safa follows suit then grips the safety ropes to hold her position at the front of the vessel.

The blue iridescent light fills the room. A solid thing of shimmering beauty that bathes them all in deep hues of colour. Malcolm and Konrad grip a pole each, ready to pull the light over them from front to back.

‘GO,’ Roland shouts and tuts to himself at not being heard. ‘I SAID GO,’ he shouts again, waving at his two workmen.

Safa stares mesmerised as the front tip of the boat simply disappears from view into the blue wall. Like it’s being pulled through a curtain. The poles move, the blue light slides and the boat disappears inch by inch.