One always drives, the other is invariably the passenger, or the driving is shared along prearranged demarcation lines, or one drives except when they’ve been drinking. The passenger navigates or stays out of it; the passenger criticises the driving either directly, or indirectly, by drawing their breath in sharply whenever there is the faintest risk of disaster; the passenger falls asleep. Whatever the pattern, it takes a deep crisis to alter it. Carol passively handing over her car keys and allowing Tony to drive was a measure of how stricken she was. Where she was a confident, assured and fast driver, he was nervous, hesitant and inconsistent. It had never become second nature to him. He still had to think about his manoeuvres and, given how easily he was distracted by thoughts of patients and killers, Carol always complained she felt like she was taking her life in her hands when she had to be his passenger. Today, her life was the least of her concerns. He programmed the satnav and set off through the late afternoon traffic.