Halfway along the walkway was a wheelchair, upturned. A woman was lying in the mud. Kirsty was bending over her.

Jake took one look and started to run.

She was Kirsty’s sister. There was no doubting it. An identical twin? Maybe. The similarities were obvious but there were major differences. The girl lying in the mud was heavily pregnant. Her face was bleached white and a fine hairline scar ran across her forehead. She lay in the mud and her eyes were bleak and hopeless. Jake had seen eyes like this before, in terminally ill patients who were alone and who had nothing left to live for. To see this expression on such a young woman was shocking.

‘Oh, Susie, I’m so sorry,’ Kirsty was saying. She was kneeling in the mud, sliding her hands under Susie’s face to lift her clear. ‘There was a rut. It was filled with water and I didn’t realise how deep it was.’

‘What’s happening?’ Jake knelt and automatically lifted the woman’s wrist. ‘You fell?’

‘You really are smart,’ Kirsty muttered, flashing him a look of fury. ‘I tipped her out of the wheelchair. Susie, what hurts? Have you wrenched your back? Don’t move.’ She sounded terrified. One hand was supporting Susie’s head; the other was holding her sister down.

Jake’s fingers had found the pulse, automatically assessing.

‘Did you hurt yourself in the fall?’ he asked, and the young woman in the mud shook her head in mute misery.

‘I’ll live.’ She put her hands out to push herself up, but Kirsty’s expression of terror had Jake helping her hold her still.

‘What do we have here?’ He held the woman’s shoulders, pressuring her not to move. ‘Can you stay still until I know the facts?’ He spoke gently but with quiet authority. ‘I don’t want you doing any more damage.’

‘She suffered a crush fracture at T7 five months ago,’ Kirsty told him in a voice that faltered with fear. ‘Incomplete paraplegia but sensation’s been returning.’