‘But I can’t see…’

‘You can feel, with your hands. There must be a handle. Something.’ Carly remembered Mr Webster telling the class the decontamination chamber had been built when there was a real threat of gas attacks. He had told them about the chutes where any clothing that might be contaminated would be stuffed but he hadn’t said what would happen after it had toppled into this small space they now found themselves in. There had to be a way to empty it surely, or did they just burn it? Drop a match through the hatch. Carly looked up fearfully as though she might see fire, her panic raging.

‘Carly! I’ve found something.’ Marie was excited, she was always so desperate to please.

‘Good girl,’ Carly said, shuffling around on her knees, arms splayed out before her until she found her sister.

‘Here, on the ground.’

Carly tightened her fingers around a metal ring and pulled as hard as she could. It didn’t move. A chink of light caught her eye. She looked up. Someone had cracked open the hatch.

‘No,’ she moaned as she rattled the handle again.

‘Three blind mice, three blind mice,’ Moustache sang softly. Slowly. She couldn’t hear Doc and she knew he’d be trying to find another way to reach them.

Despite the freezing temperature, she was boiling. She wiped her face with her sleeve.

‘Grab hold of me and pull as hard as you can.’ Carly grasped the ring, tighter now, with both hands, her sisters’ arms wrapped around her waist.

They pulled and pulled until pain seared in Carly’s shoulder joints. She felt her body might tear in two as the combined weight of the twins dragged her backwards.

Carly clenched her fingers harder. She wouldn’t let go.

Suddenly the trapdoor swung open, sending the sisters tumbling like dominoes.

Sobbing, Carly felt around until she found one of the girls and without hesitation she dragged her over to the hole and shoved her down into the blackness. Whatever was down there couldn’t be any worse than being trapped in this tiny space with Moustache still singing above them. It made Carly’s stomach contract to realize that he was relishing the chase. Wanting it almost.

‘See how they run. See how they run.’

‘Carly, I…’

‘Move,’ she snapped, cutting off Leah’s protests that it was too dark, she was too scared. She propelled her into the unknown, after Marie, then she scrambled after them both.

The tunnel was low. Damp. The stench was cloying. Their progress was slow at first. Carly felt around with her hands as they moved, terrified there’d be more to the tunnel than they knew. Different routes. The danger they might spend eternity lost in an underground maze was terrifying and something she didn’t want to be responsible for. Something else she didn’t want to be responsible for. Intermittently there were larger openings shooting off the main strip, which didn’t seem to lead anywhere, almost as though they were passing places but Carly didn’t understand why.