DogNut hawked up a big green gob of phlegm and spat it on the ground.

If only he hadn’t hesitated. If only he’d ordered them all to run while there was still time. No chance of that now. Not until they’d broken out of this ring of grown-ups.

‘Stick together,’ he shouted. ‘We need to punch our way through.’

But Robbie’s gang either hadn’t heard or were ignoring him, because they charged forward without waiting for DogNut and the others. They hacked down a couple of fathers but were immediately swamped by half the remaining sickos.

Now was DogNut’s chance. There was a big gap in the ring. He could easily get through.

Only that would mean abandoning Robbie.

No. Not again. Nobody was going to call him a coward. He was a hero, wasn’t he?

‘Help them!’

He ran at the sickos, sword swinging through the air. He took one out, but had to be careful in case he cut any of his friends. Courtney joined him, stabbing at the grown-ups with her spear. Brooke dithered, holding back, her narrow sword limp in her hand.

‘You’re going to have to fight!’ Felix yelled.

‘I don’t know how.’

‘Just kill them.’

Felix didn’t have time to say anything else, because they were on him. Five of them, trying to get in close so that he couldn’t swing his own sword. He was forced to use short, less powerful jabs and slashes, using his elbows and kicking out as well if more than one came at him at once. Marco fought his way to his side and together they managed to turn the fight back against the grown-ups.

Two of Robbie’s gang were down on the ground and bleeding, but Jackson managed to break clear of her attackers, battering them out of her way with her spear, a cold, steely look in her eyes. She had one arm round Robbie whose neck was a bloody mess. She joined up with DogNut and Courtney.

‘He’s hurt,’ she said bluntly.

‘I can’t move my arm,’ Robbie groaned.

‘We have to get back to the museum,’ said Jackson.

DogNut saw Jackson’s two friends lying in the road, unmoving.

‘What about them?’

‘Leave them,’ said Jackson. ‘They’re too badly wounded.’

‘But …’

‘Leave them!’

Jackson powered ahead, not letting any sickos stop her as she ploughed her way through them back towards Green Park, the one remaining uninjured boy from the museum helping her.

‘Stick together!’ Marco yelled. ‘We have to stick together.’

‘We’re trying to stick together, stupid,’ said Felix.

Nobody could follow Jackson, though, as the sickos turned their attentions to DogNut’s gang. Felix and Marco were completely swamped. The boys fought back and in a moment there were three dead gym bunnies at their feet, but that only made it harder for them to move without tripping up. As they fought to get clear of the pack, they kept slipping and stumbling. DogNut and the others couldn’t help them as they were all engaged in a fight of their own. DogNut and Courtney were protecting Brooke who had dropped her sword and was now completely unarmed. She was trying to scream, but the breath caught in her lungs and no sound came out.

Jackson hadn’t deserted them, however. She’d taken Robbie to safety and left her boy watching over him, and she now came belting back down the road to smash into the sickos, freeing Marco and Felix.

‘Run!’ she bellowed.

The kids didn’t need to be told twice. In a moment they were all staggering back down the road the way they’d come, exhausted. The battle had been short but intense, and it had drained their strength. They limped and hobbled, trying to ignore all the cuts and bruises they’d sustained.

The surviving sickos weren’t through yet, though. Nothing would make them give up now. They set off after the kids, bloodied and dribbling, their breath hissing through rotten teeth.

Jackson went to Robbie and got under one arm, her friend propping him up from the other side. The eight of them pushed on. They’d cleared the Ritz and were back by Green Park. A little further along was the entrance to Green Park tube station. A thought flashed through DogNut’s mind that they should steer wide of it. A tube station was the sort of dark subterranean place that sickos liked to hide out.

But the sickos were behind them, weren’t they, and, besides, he was too tired to say anything. Jackson was first past the entrance, carrying Robbie, then Courtney, but as Felix and Marco came level with the steps leading down to the station there was a shriek and a mother wearing sunglasses came flying out, knife in hand, which she brought slicing down across Felix’s face.

He yelped and the next thing they knew, several more sickos, bigger, harder and less diseased than the rest, followed the mother out.

Jackson froze in her tracks. ‘Hang on!’ she shouted.

‘No! Keep going!’ DogNut shouted back at her. ‘Get Robbie to safety! We’ll catch you up …’

There was a scream from behind and DogNut spun round to see Brooke being wrestled to the ground by two of the faster sickos from the pursuing pack. He and Courtney ran to her and laid into them, dragging them off Brooke and hacking at them. But the delay had given the other grown-ups from the first attack time to catch up and DogNut and Courtney were soon in the thick of it again. DogNut’s sword arm ached, his knees were trembling, his lungs on fire, as he cut down as many sickos as he could. Courtney was gasping for breath, she wouldn’t let up. She stood over Brooke, protecting her from any attack.

They’d had to leave Felix, though, and, blinded by the knife wound, he was defenceless. A mother fell on him and knocked him sideways, so that he collapsed over a dead body. This was all the other sickos had been waiting for: five of them dropped on to his back, clawing at him with their fingers and ripping at him with their teeth.

‘Get off ! Get off me,’ Felix sobbed, sounding like a little kid. Marco kicked at the sickos, slashing with his knife. It was no good, though – there were just too many of them – and he himself toppled over, landing on his friend and smothering him.

‘It’s all right, Felix,’ he said. ‘I’m with you. It’s all right. You’re not alone.’ He felt for Felix’s hand and held it tight, as more gym bunnies blocked out the light, swamping them.

Brooke got to her feet, trembling uncontrollably, and stood behind DogNut and Courtney.

‘We’re going to be overwhelmed,’ Courtney said as more and more sickos arrived from every direction. Everything she had ever feared was coming true. A young mother slashed at her with long nails, raking down the side of her cheek, and Courtney retaliated by clubbing her full in the face with the shaft of her spear. The mother’s face split open and she collapsed.

But it was only one. How many more of them were there?

Overwhelmed. She’d always thought it was a stupid word, and the more she used it the more stupid it seemed, like it shouldn’t have been a real word.

‘It ain’t going to happen, babes,’ said DogNut. ‘I know what you’re thinking, but we ain’t gonna be overwhelmed. We can do this.’

‘No, we can’t.’

‘Yes, we can.’ DogNut kissed her fiercely, the briefest of kisses, and then he raised his sword above his head. ‘Let’s do this. You and me, girl, let’s take it to them! DogNut and Courtney against the world!’

‘Yeah …’

Side by side, they charged at the sickos, weapons a blur, hacking to left and right. For a few seconds it looked like they might do it. Sickos fell wounded around them. It couldn’t last, though. Courtney was right. There were too many.

Brooke stood there, too terrified to move, watching in frozen panic as sickos converged on her friends.

Two fathers got close to Courtney and clung on to her spear, dragging it down. She snatched her knife from her belt and lashed out at them with her free hand, but the bigger of the two deflected her blow and the blade cut deep into her own arm. She hissed with pain and let go of the spear. She was filled with a terrible rage and gouged great chunks out of the fathers before they dropped dying at her feet. Before she could recover, however, she was jumped from behind by two more of them.