Stefan’s house was really rather splendid to Judith’s mind. It was a converted watermill with a wooden wheel that still turned lazily, but differently sized rectangular glass windows had subsequently been cut into the building. It was both pleasingly old-fashioned and modern at the same time.

She went and looked at Stefan’s car in the driveway. Judith knew nothing about cars, and cared even less, so all she could tell was that it was grey in colour, and it was gleaming, not a spot of dirt on it anywhere. She could see no other tyre tracks in the gravel, or any other clues that suggested that perhaps Stefan had left the house in a different vehicle.

She went for a walk around the garden, trying to work out where the sound of the gunshot might have come from, but it was hard to place herself accurately when her only reference point was from a position in the river below the height of the bulrushes.

In fact, it took only a few minutes of walking around and inspecting the reed bed by the riverbank for Judith to realise that she didn’t even know what she was looking for. A drop of blood on a blade of grass? A muddy footprint?

Judith looked at the wooden wheel turning on the side of the house, and the millpond in front of it. Despite the heat of the day, the water here was dark and Judith shivered at the thought of it. There was something about still bodies of water that spooked her. Although, as she looked, she could see that the water wasn’t quite still. There was a slight current tugging at the surface. Where was the water going?

Judith walked around the edge of the pond until she saw that it fed into a river that was about ten feet across. Where the millpond ended and the river began, there was a narrow brick causeway that crossed from one side of the garden to the other.

Judith considered the river beyond the dam. It had to feed back into the Thames somehow. But it was hard to see exactly how, as Stefan had allowed this section of the garden to grow wild, and the water soon slipped under dense shrubs and bushes that crowded in from both banks.

With a sigh, Judith realised she’d have to follow the course of the river. She had to be thorough. So she pushed her way through the bushes, branches whipping her body, cobwebs sticking to her face and hair as she struggled to the other side.

Once there, Judith was disappointed. It was even wilder in this corner of the garden, but she could see that the river passed through some iron bars onto a concrete weir that fed the water back into the Thames. There was nothing of interest to see.