‘I always think a case is like driving from here to the Gaspé. A great long distance and I can’t see the end. But I don’t have to. All I have to do is keep throwing light in front of me, and follow the headlights. Eventually I’ll get there.’

‘Like Diogenes with his lamp?’

‘In reverse. He was looking for one honest man. I’m looking for a murderer.’

‘Be careful. The murderer can see the man with the lamp coming.’

‘One more question, doctor. How would someone give her niacin?’

‘It’s water soluble, but quite bitter. Coffee would probably mask it. Orange juice I guess.’

‘Tea?’

‘Less likely. It’s not strong enough.’

She gathered her things and taking her key from her pocket she pointed it out the window and pressed a small button. Outside a car came to life, headlights on and presumably the heater struggling to warm the inside. Of all the inventions in the last twenty years Gamache knew the two best were car seat warmers and automatic ignition. Too bad for Richard Lyon he’d invented magnetized soldiers instead.

Gamache walked her to the door, but just as she was about to leave something else occurred to him. ‘What do you know about Eleanor de Poitiers?’

Dr Harris paused for a moment.

‘Nothing. Who is she?’

‘How about King Henry the Second?’

‘King Henry the Second? You’re not seriously asking me about some long dead British royal? My favorite was Ethelred the Unready. Will he do?’

‘What a repertoire you have. Ethelred and Captain Crunch.’

‘A catholic education. Sorry I couldn’t help.’

‘Niacin.’ He pointed to the dossier still on their table. ‘You saved the day.’

She felt absurdly pleased.

‘Actually,’ he said as he helped her into her coat, ‘there is one more thing. Eleanor of Aquitaine.’

‘Oh, that’s easy. The Lion in Winter.’

‘Honey, could you get the door? I’m in my studio,’ Clara called. There was no answer. ‘Never mind,’ she called after the second knock. ‘I’ll get it. Don’t bother yourself. No really. I don’t mind.’ She yelled the last at the closed door to his studio. She was pretty certain he was in there playing free cell.

It was unusual to hear a knock. Most of the people they knew walked right in. Most helped themselves to whatever was in the fridge. Peter and Clara sometimes came home to find Ruth asleep on their sofa, a glass of Scotch and the Times Literary Review on the hassock in front of her. Once they found Gabri in the bath. Apparently the hot water in the B. & B. had run out, and so had Gabri.

Clara yanked open the door, prepared for the blast of cold air and not totally surprised to see Chief Inspector Gamache, though a tiny part of her still hoped it might be the chief curator of the MOMA, come to see her works.