“Shit!” In desperation, Jem swung herself off the ledge and into the water. Gasping against the sudden shock of the cold, she wrapped a fist in Rosie’s hood and pressed the tube to Rosie’s mouth. “Breathe through it,” she yelled, but there was no sign of Rosie complying, and the alarm on the defib kicked up a pitch. Jem fumbled blindly, finding Rosie’s mouth again and ramming the tube against her lips. “Rosie! Fucking breathe through the fucking tube!”

That got the message through. Rosie pursed her lips, missed her target, and then snagged the base of the tube, almost taking Jem’s finger with it.

“That’s it, love,” Jem said as water shot from the plastic opening. She found a hollow in the wall and shoved her free hand into it, stabilising them both. “That’s it, just breathe.” She saw Rosie take an experimental breath and then another with more confidence, and the defib fell silent. “You’re doing really well,” Jem said, her entire body shaking with relief and excess adrenaline. “They’ll be here any minute.”

She didn’t know whether Rosie could hear her, but she felt Rosie’s head rest against her chest as Rosie put an arm around her and drew her close. The tube, sturdy enough to keep itself clear of the water, bobbed gently with every inhalation, and Jem fixated on it in the dim light, reassured by the strength of Rosie’s hold on her and by the defib’s continued quiescence. Huddled over Rosie, she was able to shield her from the worst of the passing wreckage, barely registering the frequent hits she took to her back and shoulders. Her breaths wheezed out far more slowly than Rosie’s, and when at last she heard the first distant call of the rescue team, she wasn’t able to respond to them.

“They’re coming,” she whispered through chattering teeth. “We’ll be out of here in no time.”

Powerful lights slashed across the water as multiple voices shouted their names.

“Here!” She didn’t manage a yell, but someone must have heard her, because an excited clamour rose up and boots stomped in their direction.

“Jem!”

“Over here!”

Letting go of Rosie’s hood for a second, she lobbed a chunk of brick onto the ledge. That did the trick, and bedlam erupted above them as a team of five threw down their kit and tools and spoke at once. Spence was the only paramedic amongst them, and Jem realised the remainder were uniformed police officers.

“Fucking hell,” Spence said. “Is she breathing?”

“Yes.” Jem was still watching the tube. “Someone will have to—” she coughed, rocking them both, “have to brace her right thigh and cut the metal. Don’t try to pull it. It’s stuck fast near her femur.”