Frost nodded towards the bucket. ‘No thanks, Ada – I went before I came out.’ He introduced her to Gilmore. ‘This is Ada Perkins, the Swedish au pair.’

The woman grunted. ‘You’re not half as funny as you think you are, Jack Frost.’ She jerked a bony thumb towards a door at the end of the passage. ‘There’s a policeman in the kitchen drinking tea.’

‘Then let’s start in the kitchen,’ said Frost.

It was a spacious, no-expense-spared kitchen, fitted out in solid oak with marble worktops, burnished copper cookware on the walls and miniature hand-operated water pumps instead of taps over the sink. A black Aga disguised to look like an old coal-fired cooking range breathed the warm crunchy smell of baking bread. Black-moustached PC Jordan, twenty-six, his tunic unbuttoned, was seated at a scrubbed pine designer table drinking tea from a thick designer mug. He jumped up to attention as the detectives entered, but Frost waved him to sit and dragged up a chair alongside him. Gilmore did the same.

‘I suppose you want some tea?’ said Ada and, without waiting for their reply, poured two teas from a brown teapot, pushed the sugar bowl across, then shuffled out, muttering something about having work to do.

Frost found a tea towel and dried his wet hair. ‘This is Frank Gilmore.’

‘Hi, Frank,’ said Jordan, offering his hand.

The hand was ignored. ‘Detective Sergeant Gilmore,’ came the icy correction. ‘And button up that jacket.’ Start as you mean to go on. Don’t let the lower ranks get too familiar or they’ll walk all over you.