The thin house in Clarges Street that had been rented by the Tremaines was standing empty. They got the key from the factor and let themselves in, then searched high and low, Harry crawling along the floor-hoards, to see if one bloodstain might have been overlooked.

‘She might have been killed here,’ said Harry. ‘She certainly wasn’t killed in that boat or there would have been a lot more blood.’

‘The pathologist said that costume had been put on her after her death and the blood from the wound on her chest had seeped through the material.’

‘You didn’t tell me that.’

‘You’re not in the force and I have plenty of other cases taking up my time, which reminds me, if you’re finished here I’d like to get back to the Yard.’

‘I hate being passed over just because I’m a woman,’ raged Rose, walking up and down her sitting-room. ‘I’d like to show him I can detect better than he can. I’d like to go down to Apton Magna and get the parents’ reaction to the fact that their precious son was consorting with a criminal. But how are we to get out of the house without Turner and two footmen following us?’

‘I’ve an idea,’ said Daisy. ‘’Member that ladder we used to get over the garden wall? It’s at the side of the garden. If we left, say, about five in the morning, the staff would still be asleep. We could sneak out and get the early-morning train at Paddington.’

‘We’ll do it!’ said Rose.

Harry set out to find the temporary footman who had worked for the Tremaines. His name was Will Hubbard and his address was number five Sweetwater Lane in the City.

After the Great Fire, plans had been drawn up to build a modern City out of the ashes, with airy streets and wide boulevards. But there turned out to be so many claims from property owners who would demand heavy compensation if, say, a street ran through where their buildings used to be, that the new City, the commercial hub of London, rose again following the old medieval pattern of narrow winding lanes.

Sweetwater Lane was just north of Ludgate Circus and consisted of two lines of black tenements. Number five had a great quantity of bell-pulls. Harry pulled several of them. The front door was opened by a lever on each landing. When the door opened, several voices asked him what he wanted.

‘Will Hubbard,’ he shouted. There was a sudden silence and then the sound of slamming doors.

He made his way up, knocking on door after door, but nobody answered until, at the very top, an elderly lady opened the door a little. ‘I am Captain Cathcart,’ said Harry. ‘I am helping Scotland Yard with an investigation.’

The door began to close. He put his foot in it, fished out a guinea and held it up. The door opened wide. She snatched the guinea in a claw-like hand.