He was holding his javelin two-handed, jabbing with the point, keeping the grown-ups back, but not doing a lot of damage. Brooke was scared, but working her short sword, holding her own. This was defence, not attack. They needed to move.

And then a space was opened up again. Ed and Kyle had cleared a way through up front, and Lewis wondered why he’d ever had any doubts about Ed.

The two of them were a killing machine, cutting through the grown-ups like a piece of farm machinery, not stopping, not seeming to think, working together in sync as if they shared one brain, protecting each other and timing their swings so that they didn’t get tangled. There was an open area all around them, carpeted with fallen bodies. Their blades and clothing were already wet with blood, and they were shouting for the others to catch up.

Lewis, Ebenezer and Brooke fell in with them. Ed and Kyle driving on at the front, Lewis and Brooke taking the flanks, Ebenezer turning to face backwards and protect their rear.

The grown-ups didn’t have the brains to hold back, just kept on coming, throwing themselves on to the kids’ weapons. They blundered in too close and got cut or stabbed, or blinded by a slash across the face.

Lewis could hear Kyle laughing and Ed grunting with each strike, as step by painful step they forced their way towards a gap in the hedge.

Brooke was wailing like someone on a roller-coaster, waving her sword madly, all idea of technique forgotten. Ebenezer was calling out to God. Lewis kept quiet, concentrating, getting into a rhythm, learning the best way to use the katana – a slash to the right, to the left, back to the right and then in with the point.

Somehow Ed got them off the road and into the fields where the grown-ups were less tightly packed. They could move faster now, driving through the scattered mothers and fathers, leaving behind a trail of dead and wounded. Lewis was already shattered. This was hard work – running and fighting. He could hear Brooke screaming with each swing of her blade, moving closer to panic. They had to hold it together. If you lost your nerve you were dead.

He risked glancing ahead. There were the buildings they were aiming for, on the other side of the field, a cluster of them behind a row of low trees. A long way, though. Two hundred metres maybe. With grown-ups all the way.