The Extremes by Christopher Priest

British-born Teresa Simons returns to England after the death of her husband, an FBI agent, who was killed by an out-of-control gunman while on assignment in Texas. A shocking coincidence has drawn her to the run-down south coast town of Bulverton, where a gunman's massacre has haunting similarities to the murders in Texas.

Desperate to unravel the mystery, Teresa turns to the virtual reality world of Extreme Experience, ExEx, now commercially available since she trained on it in the US. The best and worst of human experience can be found in ExEx, and in the extremes of violence Teresa finds that past and present combine...