What must have been only a few seconds later, he reached out to grip the cardboard edge of the stand. He was teetering on his cliff again now, so close to plummeting over the edge. Even though his eyes were fixed on the DVD display, all of his senses seemed hyper-sharp. He could hear the trolley wheels rumbling in the next aisle. His skin prickled and his breath caught in his throat. Even though the aisles were almost empty, just a few determined early birds come to get their shopping before the morning rush, he felt as if he was in the midst of a jam-packed, crowded city.

On his cliff, he could feel air, cold and beckoning, beneath his toes. He could sense pebbles and scree skittering down the face of the rocks as the cliff below them started to crumble.

Push through, he told himself. It’s a supermarket, for God’s sake, full of carrots and celery, currant buns and tins of soup, not a war zone. Keep going. Just keep walking. Get what you need.

He put the DVD back, fumbling to get it into the cardboard slot, and then made his way to the end of the aisle at the back of the shop. From there, he moved along the ends of the rows, stepping stone to stepping stone, scanning the lengths of the shelves for a hint of any Asian foodstuffs – coconut milk, noodles, dark shiny bottles of soy sauce – but he couldn’t see anything like it. When he got to the place he’d always found them before, the shelf was full of baked beans and pots of instant noodles. It seemed as if someone had moved around every single flipping thing in the supermarket just to confound him.

He stared at a can of spaghetti hoops with miniature frankfurters, and his hand shot out to grip the shelf, squeezing it so hard the metal edges dug into his fingers.

Focus, Brody. Focus.

He couldn’t even pick out single items on the shelves now. All the colours and shapes were blurring together. He stumbled blindly down one aisle and into the next, only pausing when his chest felt so tight that he had to stand still to draw breath. By some bizarre, God-given stroke of luck, he found himself staring at a small glass bottle full of sour brown liquid, a curving dragon emblazoned across the label.

Fish sauce.

He grabbed it off the shelf and hugged it to his chest, closing his eyes with sheer relief. He couldn’t imagine feeling any more triumphant than if he’d climbed Everest in a single leap. But just as he was about to open his eyes and head for the bank of tills at the front of the shop, there was an almighty crash behind him. The bottle slipped through his sweaty fingers, and he only just managed to catch it again before it smashed onto the floor.

‘Sorry, love,’ a woman said cheerily, from a few feet away. ‘These trolleys have a mind of their own!’ And she began picking up the cans of bamboo shoots and water chestnuts she’d just knocked off the shelf.