One.
The well-practised devotee of the genre knows that the story doesn’t really kick off until there’s death. Being impatient creatures, we prefer to have death right off the bat, but we can bide our time if the prelude to death lets us clue for looks (so long as the promise of death is ripe and not too delayed). Cold cases are not ideal but acceptable in a pinch if one is constrained to only visual adaptations. If your senses weren’t already tingling, they should certainly come alive as soon as death pays a visit. And remember, most murderers are somewhat reasonable and don’t like to exceed more than half a dozen bodies at a time, so take a headcount and make sure you’ve got favourable odds of surviving.
Two.
Dark and stormy nights are the most dead giveaways of all dead giveaways. A fugue of disastrous weather events to set the scene and form the silent Greek chorus to the unfolding tragedy. There are rules to this sort of thing, like maritime signal flags. Expect to face stranding, whether physically or metaphorically, as there will be some combination of a blackout and/or cut landlines and/or no cell service and/or banging bits of loose window shutters and the like. You don’t have to be a boy scout to have a pocket torch and fully charged phone, now, do you? As soon as you receive that unexpected invitation to a country estate or island getaway, make sure to start packing matches and batteries.
Three.
People remain affronted by the idea of eavesdropping, but there’s no room for tidy little morals when you’re in the cast of a murder mystery. If someone is so foolish as to discuss grudges and murders in whispering galleries or by open windows, it serves them right to be snooped upon. Of course, there’s a non-trivial chance that having pricked ears will put you in the queue of murderous intentions, but then again, it would serve you right if you’re stupid enough to try blackmail or incapable of mastering your emotions when next you face the person in question… Stay cool; stay not-stupid.
Four.
An old schoolmistress, a tutor, a baker, a candlestick maker—any of them will do. They must be underestimated and seemingly innocuous on first blush. Occasionally they may be roaring racists because, well, old people, but that doesn’t detract from their value as people to stir nests and get killed. When one is running from a bear, you only have to be faster than the person behind you, and the retired character has got to be one of the people behind you. Never believe them (or anyone, for that matter) who says they’re wheelchair-bound and never underestimate them even if they are.
Five.
Young people are largely classified as boorish somethings, insufferable children, languishing lovers, or estranged prodigy. It’s unusual to see all three of these together, but the Venn diagrams may even be circles in the rarer of cases. Murderers are not above being children, so you’ve got even more reasons to avoid those little buggers, but your odds of success are good if you can get the young people intoxicated in order so they can spill your guts to you (though, naturally, only by an open window or an adjacent bedroom). The main caveat here is the last category; estranged prodigy are highly unstable and seem to swing between weeping uncontrollably because they want to be loved by some parent they’ve never met or planning cold-blooded murder in order to mete out whatever deluded idea of justice they have. Languishing lovers are more prone to impulsive outburst (and murders) so it’s better to placate than aggravate them.
Six.
Secrets are the glue that holds a good murder together. Sex, money, power, revenge—the more secrets the better, with a mean of at least sixty percent and a standard deviation of twenty percent. It’s got to be a fairly uniform distribution, too, so try to make sure you didn’t recently become a bigamist or take a bribe. The best time for revealing secrets in a group setting is usually going to be a seance since everyone is too preoccupied with their own secrets. The supernatural is usually a lost cause, because anyone who’s been around the block even once will instantly know that the supernatural is a farce, but psychology is a funny thing and you had best use it to your advantage.
