‘Tell me what you know,’ said Gamache to Lemieux.

This was one of Beauvoir’s favorite moments. The beginning of another mystery. But Gamache knew this mystery, like all murders, had begun long ago. This was neither the beginning nor the end.

Gamache walked a few paces further onto the frozen lake, his boots breaking through the thin crust of snow to the softer layer beneath. Gamache felt the telltale trickle down his ankles and knew snow had found its way into his boots.

‘According to witnesses the victim simply collapsed,’ said Lemieux, watching the chief, trying to read whether he was satisfied with his answers. He looked uncomfortable and Lemieux privately cringed. Had he done something wrong already? ‘They tried to revive her, thinking it was a heart attack, then they got her into a truck and took her to the hospital.’

‘So they trampled all over the murder scene,’ said Beauvoir, as though it had been Lemieux’s fault.

‘Yes sir. They were doing their best, I think.’

Lemieux waited for another rebuke, but none came. Instead Beauvoir huffed and Gamache said, ‘Go on.’

‘The emergency room physician, Dr Lambert, called the police about half an hour later. At around eleven thirty this morning. He said he had a suspicious death. Said he’d called in the coroner and it looked as though the victim had been electrocuted. As I said, officially he called it a suspicious death, he has to until it’s ruled a homicide, but when we arrived he made it clear he had no doubts. She was murdered.’

‘Please use her name, agent,’ said Gamache, without reproach. ‘We need to see Madame de Poitiers as a person.’

‘Yes sir. She, Madame de Poitiers, was electrocuted right here.’

It was what Lemieux had said on the phone, and hearing it in his office had sounded strange enough to Gamache, but standing at the scene it was even more bizarre.

How does someone get electrocuted in the middle of a frozen lake? You used to be able to electrocute someone in a bathtub but that was before most appliances had automatic shut-offs. Toss a toaster into your spouse’s bath these days and all you’ll get is a blown fuse, a ruined appliance and a very pissed-off sweetheart.

No. It was almost impossible to electrocute someone these days, unless you were the governor of Texas. To do it on a frozen lake, in front of dozens of witnesses, was lunacy.

Someone had been insane enough to try.

Someone had been brilliant enough to succeed.

How? Gamache turned slowly, but nothing new presented itself. Certainly there were no vintage televisions or toasters smoldering on the ice. But there were three aluminum lawn chairs sitting on the snow, one toppled over. Towering behind the chairs was what looked like a huge chrome mushroom, fifteen feet high. About twenty feet off to the left was a set of bleachers.