Simon buttoned the white coat over his clothes and turned to River who was dressed as a nurse. “Ready?” he asked.

She nodded. Opening the door to the supply closet she peered out. “No-one watching.”

They stepped out into the corridor and walked purposefully towards the examination suites. People passed them by, but no-one took any notice of a doctor and nurse who looked like they belonged.

“In here,” Simon said at a door marked Fertility Clinic. They slid inside and locked the door behind them. “It shouldn’t take long,” he added as he headed for the main bank of equipment. “I’m pretty sure I know what the problem is, but … just make sure no-one wants to use this room, okay?”

“Okay.” She stayed by the door, watching through the small window.

Simon switched on the machinery and opened his bag, waiting for the computer to boot up. Symbols appeared on the screen, and he began to input information.

River glanced around at him, admiring the efficiency of his movements, the way he did nothing that wasn’t needed. He was such a good doctor, could have saved so many lives, but he’d given it all up to save her instead. She felt so grateful to him that she could never fully put it into words. She looked back outside.

He slid the samples he’d brought into the diagnostic unit, putting a memory tab into the slot to collect the results. Choosing the programme he needed, he pressed start. The machinery hummed into life and started to collate.

As he waited he contemplated what might happen as a result of this. If Kaylee was never going to get the second child she wanted, if he had to tell her that he was less than a man …

Suddenly River was at his side, grabbing his arm. “Simon,” she said urgently.

“What is it?” he asked, watching the bar that showed the progression of the download.

“They need us.”

“Who?” He looked over his shoulder at her.

“Serenity. Now.”

His eyes widened. “Someone’s hurt?”

She nodded. “Hurry.”

As she spoke the comlink in his pocket began to vib