My name is Cheryl Phillips. I am forty-eight years old and an underwriter for an insurance company in Hartford, Connecticut, which means that from Monday to Friday I estimate the likelihood of terrible things happening to people.

Every other Saturday, I arrange them.

I am the Keeper of a Call of Cthulhu campaign that has been running at my dining room table since March of 1998. Five players, all from my office: two from claims, one actuary, one from the mail room and one from legal, who is the most frightened of them all and has the most reason to be. My husband Carl makes chili and stays out of it. He says he can hear the screaming from the den. That is an exaggeration. Mostly.

Call of Cthulhu is a roleplaying game, published by Chaosium since 1981 and based on the horror stories of H. P. Lovecraft. We play the fifth edition rules. If you have played Dungeons & Dragons, forget most of it. Nobody in this game is a hero. The players are investigators: professors, reporters, doctors, private detectives, people with a little money and too much curiosity. Ordinary people who look into something they should not have looked into, and discover that the universe is very old and very large and does not care about them at all.

Investigators do not get stronger. They get smarter, and then they get frightened, and then they get careful, and if they are lucky they get out. Nearly everything is rolled on percentile dice. Your skills are percentages. Your library use is 60%; roll 60 or under and you found the article. Your firearms skill is 25%; I would not count on the revolver.

I am the Keeper. I write the mystery, play every person they meet, and keep the secrets behind my screen until they earn them.

It is 1924. Coolidge is in the White House, Prohibition is the law and nobody pays it much mind on the North Shore, and Essex County, Massachusetts, is fishing towns and salt marsh and old houses with widow's walks. It is also, in our version, home to the town of Arkham and its Miskatonic University, and to Kingsport down the coast, which are Lovecraft's towns, and to a few places of my own invention that you won't find on any map, the chief of which is a fishing village called Wexcombe. Nobody you know has ever heard of it. That is how Wexcombe likes it.

The campaign has run in three parts:

• The Late Mr. Halpern's Library (March to October 1998). An Arkham book collector dies and leaves his estate in a tangle, and our investigators are hired to sort out the books. They sort them out. One of the books sorts them out, too.
• Fog at Kingsport (October 1998 to May 1999). A fog that comes in off the water at the same hour every night, and the people who walk out into it. We lost our first investigator in this one. See the fallen.
• The Tide-Bell of Wexcombe (June 1999 to present). A missing Miskatonic professor, three drownings in one summer, and a chapel bell that rings at low tide in a chapel that has had no bell since 1870. In progress. Very much in progress.

1. Seven o'clock sharp. Chili at seven, dice at seven-thirty, done by midnight. Usually.
2. Players roll their own dice in the open. I roll mine behind the screen, and you will never know whether I just rolled a 03 or a 97. I like it that way.
3. Your investigator knows what your investigator knows. If you have read Lovecraft and your character has not, keep it to yourself. Brian, I am looking at you.
4. Talk like it's 1924 when you can. A dime in the jar for anything that wasn't invented yet. The jar paid for our pizza in July.
5. When an investigator dies or goes permanently mad, the player builds a new one at once, and I find a way to bring them in by the next session. Nobody sits out.
6. Do not split the party after dark. (They always split the party after dark.)
7. Nothing that happens at this table is discussed at the office before ten on Monday morning. Claims is very bad at this.

Every investigator has Sanity points, and they are the most important number on the sheet. You start with your POW (your strength of will) times five. Our five began somewhere between 55 and 75.

When an investigator sees something terrible, I call for a Sanity roll. Roll percentile dice. If you roll your current Sanity or under, you keep your head, mostly, and lose a little. If you roll over, you lose more. I write it like this: 1/1D6. That means you lose 1 point if you make the roll and one six-sided die's worth if you fail. A dead body might be 0/1D3. The things under Chapel Rock are rather more than that.

Here is the cruel part. Your Sanity goes down, but the roll is always against your current Sanity. So the more you have seen, the harder it is to keep your head about the next thing. It snowballs. That is the point.

Temporary insanity. Lose 5 or more points in one go and you make an Idea roll. If you succeed, you understand exactly what you've seen, and you go temporarily mad: you faint, or run, or scream, or freeze, for a while. Yes, failing that roll is better. Yes, the players hate this rule.

Indefinite insanity. Lose a fifth of your current Sanity within one game hour and you are indefinitely insane: months of game time in a sanitarium, or a phobia or a mania that stays with you.

Permanent insanity. Reach zero and your investigator is gone. Not dead. Worse. They are retired to a quiet room somewhere and you make a new one.

And there is Cthulhu Mythos, the skill. Every time an investigator learns something true about the way the world really works, from a book or the hard way, they gain points in it, and their maximum Sanity drops to 99 minus that skill. Knowledge costs. That is the whole game in two sentences.

Sanity can come back, a little, from finishing a case, from rest and treatment, and from my rare and terrible mercy. Professor Ivey got 8 back in May for putting an end to the fog. He has since spent them all.