‘You’ve really thought this through,’ she eventually said.

‘It’s all I could think about last night. I was so worried for Stefan. What if he’s been shot, and the gunman’s escaped? In fact, what if Stefan is right now lying bleeding in a ditch?’

‘I don’t think he’s lying in a ditch. I’m sure there’s some very innocent explanation for all of this. There wasn’t any indication at his property that anything untoward had happened, and it’s not that unusual for someone to ignore their phone. It’s holiday season. People are away. I’m sure Mr Dunwoody will turn up in the next few days. And the moment he does, I’ll let you know. Really, there’s nothing to worry about.’

DS Malik ended the call by thanking Judith for being such a civic-minded neighbour and then rung off.

Afterwards, Judith lay in bed not knowing what to do. Was DS Malik right? Was there in fact a far more innocent explanation for what she’d heard the night before? After all, Judith knew one thing for sure: murders just didn’t happen in Marlow.

She decided to put the matter from her mind, and get on with her work for the day.

When Judith had inherited her house from her great aunt Betty in 1976, she’d also received a portfolio of shares that provided her with a modest income, so she didn’t have much need to work for a living, but nothing would have ever made Judith give up her job. She loved it too much.

Judith compiled crosswords for the national newspapers. She set two or three a week, and the hours she spent each day working on the puzzles were a cherished refuge for her mind. When she was setting a crossword, a calm descended on her and she could lose herself for whole stretches of time as she carefully worked through all the permutations of a particularly satisfying anagram, or considered an elegant phrase or word which could be interpreted in more than one way.

Judith crossed her drawing room to the card table by the bay window and smoothed down the green baize with her hand. Next she reached up onto a shelf and pulled down a sheet of squared mathematical paper. She then chose a 2B pencil from a mug of 2B pencils and, even though it didn’t need sharpening, she pushed the pencil into her metal desk sharpener. It gripped the end, the old electric motor clattering as it spun, and the pencil Judith removed a few seconds later wasn’t so much a writing implement as a lethal weapon.

Judith smiled to herself. A fresh pencil. The empty squares on the paper in front of her. The fight ahead.