The Darkness Within: A heart-pounding thriller that will leave you reeling. Lisa Stone

he can manage alone and be independent, I suppose,’ Elizabeth offered. ‘But he gets so angry with me. It’s frightening.’ She had yet to tell Andrew what Dr Shah had said about the side effects of the medication having nothing to do with Jacob’s behaviour.

      ‘I suppose it might do him some good,’ Andrew said reflectively. ‘Make him realize he’s not invincible and he needs us. Try not to worry, I’m sure he’ll phone you soon.’

      ‘Do you think so?’ Elizabeth asked uncertainly. ‘I am worried.’

      ‘Once he needs a lift home, he’ll phone. I can’t see him using the buses. It will be an uncomfortably long journey.’

      ‘I’ll wait around here for a while then,’ she said, only partly reassured.

      The ticket had an hour to run and Elizabeth sat in the car with her side window slightly lowered to let in some fresh air, resisting the urge to phone Jacob. She was also thinking about what Dr Shah had said. Not so much about Jacob needing his independence, nor him telling her that the medication wasn’t responsible for Jacob’s behaviour, but what he’d said about cutting the nerves to Jacob’s heart, and that they’d never grow back. She couldn’t remember being told that before the operation but then there’d been so much to take in it might have been mentioned and she’d forgotten. Now his words stuck and resonated with unsettling familiarity, for that was exactly what if felt like to her – the nerves to Jacob’s heart had been cut, severing emotion. Denervation, Dr Shah had called it. He’d said that it was nothing to worry about, part of the procedure, and had no negative after-effects. But how could he be sure? Doctors didn’t know everything. They didn’t get it right all the time. She checked her phone for messages – there were none – and then googled denervation.

      A surprisingly long list of websites offering information on denervation appeared and opening the first, she quickly learned that radio-frequency denervation was most commonly used to treat chronic back pain. The nerves around the joints in the back were deactivated, thus alleviating the symptoms. But this wasn’t the denervation Jacob had had and she googled again, this time typing in denervation and heart transplants