The crime bug bit me the day my father died although I didn’t realise it until much later. I was only three at the time, so my memories are blurred but the hints my mother dropped over the years sharpened a different kind of focus.

She would refer to the secretive work he had done and to the infamous spies he knew, usually after a sherry or three. Then there were the oblique mentions of his sudden, untimely death, his glamorous first wife and a mysterious fire that had burned their London house down. Mix in his Oxford education, murmurs of British Intelligence, Colonial missions lost in the mists of time and the ramifications were obvious.

My dad was a spy and he had probably been murdered. Or he could still be alive somewhere, a prisoner or even a defector. Almost every kid who has lost a parent thinks they might secretly be alive. Not every kid has a writer’s nose for a story or the tantalising details that could not be explained away.

I used to scan faces at airports and wonder if one of them was my dad. I knew in my heart that he was dead, but I still picked at that murder theory.  Yes, he probably did die of peritonitis as I was told. But then again, you never know. You never know because people are far more complex than we think and, as I have learned, capable of anything.

It is that refusal to take anything at face value that has fuelled my fascination with crime and led me down many dark alleyways. Some existed only in my mind. Others were more physical. I spent my days at my Devonian convent boarding school devouring Agatha Christie who was coincidentally born in Torquay, where my school was located. Christie loved a coincidence and I identified strongly with this woman who had developed her expertise in poisons after volunteering as a nurse during the war and assisting a hospital pharmacist.

Later, I soaked up Le Carré, PD James and every hard-boiled hack I could find before moving on to true crime, psychological thrillers and the cool, spare prose of Scandi noir. A crime thriller or mystery is both interactive and intensely intimate. We try to get inside the mind of the writer or protagonist so that we can solve the clues even as we anticipate the ending. It’s a rush when we get it right. A gut punch when we’re wrong. This is a visceral experience like no other and we can do it from the comfort of our living rooms.

Often the characters are people just like us except that something sinister has happened to them. They give us the chance to live vicariously, to flirt with danger. They allow us to exercise our minds and emotions in a way we may never experience in real life. Except that there is always the chance that we might. Which is why we keep getting back on the rollercoaster for another ride.

The high stakes counterbalance the humdrum chaos of our own lives, especially if that chaos is domestic. Female crime fans outnumber male by a significant percentage, partly because their own lives are so full and fragmented with multiple responsibilities. Crime fiction lends order, especially if it is a police procedural. More than that, it takes us out of the ordinary. Good and evil are clear-cut. Underlying themes are Biblical or mythical in proportion. Passion, revenge, mayhem and murder stir the blood in the most domestically dulled of veins.

I understand that need for a crime fix. I am also driven to supply it. I feed that supply through words, my favourite weapon. But I began to realise that the one barrier to crime fans was the thing they craved most, knowledge. If a reader or viewer does not understand a phrase or term used, then it adds friction to their experience. They cannot fully immerse themselves in the mystery or the solving of it and are therefore robbed of their full rush.

Crime readers are a discerning bunch. They thrive on fact and thorough research underpinning fiction. The blue line between true crime and crime fiction grows ever thinner as writers serve up stories with a palatable coating that barely disguises their roots in real life. Readers crave authenticity, but they don’t want it to get in the way of a good plot.

In trying to solve that problem like so many others, I came up with the idea of a crime dictionary, one that would not simply give definitions but also enough context and background to oil the wheels of the rollercoaster. With it in hand, crime fans can simply jump on and enjoy one hell of a ride. That, after all, is the reason we do it.

My crime dictionary is the culmination of my own restless search for answers. I am as guilty as anyone of needing to impose order. In my case, it is through my love of story and words, two gifts my father bequeathed me. I no longer search for his face in crowds. But I will always wonder. What I did not want was for any fellow crime fan to be left wondering too.

I wanted everyone to be able to stand at the shoulder of monsters unencumbered, to have a companion on the ride, a friend who holds your hand as you scream at the scary bits. It is also the friend I wanted on my unending search for my father, something that makes sense of the unexplained and unimaginable. After all, isn’t that why so many of us read crime?

Extracted from From Aconite To The Zodiac Killer, The Dictionary of Crime