This is the sort of thing nobody ever believes, but I’ve got to tell someone: my weekly gaming group is haunted. The spirit’s name is Ghost Geoff, and through the creaking front door he arrives, always well in advance of Real Geoff.

As of yet we have no idea why this apparition visits our home. Was he murdered in our living room, a secret shamefully concealed by the previous owners? Was the foundation laid above an ancient burial ground? Is he just sort of pissed that Real Geoff is always like an hour and a half late?

At night, he fills my sleeping head with unclear visions, images of places far-off and impossible. I’ve attempted oneiromancy, the divination of dreams, but the visions he sends… well, they’re idiotic, is what they are. If Ghost Geoff wants me to figure out what he needs, he’s going to have to be a lot clearer.

Solving the mystery…ium!

Right there, that’s what Mysterium is about. There’s this big old house, just a tad smaller than mine —the veranda only goes around the front and the wine cellar’s contents aren’t nearly so comprehensive — and some previous wrong has forced a spirit to linger there, yearning for a team of mediums to solve the century-old crime and set him free.

How will they release the spirit’s chained torment? Well, by playing Dixit, of course.

Here’s how it works. Each game sees a random selection of suspects, rooms, and possible murder weapons laid across the table. In secret, whoever is playing the ghost creates up a face-down trio for each investigator, a single set of clues that indicate what, where, and who might have killed the spirit when it was yet alive. Then, each investigator works to figure out all three of their individual clues.

Four dreams, one location. Obvious.

The problem is that our spiritual investigators only have a week to solve the mystery and this particular ghost isn’t actually very expressive. It can only hint at the different clues through dreams in the form of Dixit-like cards packed with conflicting detail and strange imagery. Unfortunately, these dreams are often peculiar enough that not only will the investigator struggle to decipher what the ghost meant by a particular vision, but the ghost will also struggle to figure out which vision to give, especially because the player controlling the spirit only has a limited selection of dream cards at any given time.

This is the role every investigator complains about until they get a turn as the spirit. “This is the dumbest possible clue of all time,” they’ll say, glaring daggers at the apparently-not-so-incorporeal spirit. Later, when they finally get a turn as the spirit, they’ll stare blankly at the six dream cards in their hand, wondering how in the hell they’re going to get someone to guess that clue with these cards.

It doesn’t help the situation that the way we humans perceive the world is so infuriatingly inconsistent. Success in Mysterium isn’t merely a matter of matching a dream to a clue, but matching a dream to a clue to a player. When it comes to the person sitting on your left, their odd way of interpreting things has never been as clear as when you’re certain of a clue, you’re staring right at it, and then they go and say something crazy like, “Maybe the bird in the dream means the murder took place in the cave?” And if you think that’s bad, it’s even more infuriating when they turn out to be right.

Does a particular card represent color? The outdoors? A certain shape, maybe rounded or sharp? That you’re looking for certain imagery, like birds or chairs? Or just a particular vibe, a dreary landscape indicating the dreary sailor?

For example, let’s say an investigator is looking at three different murder weapons, such as a gas cylinder (the actual clue), a fork for cocktail weenies, and some rat poison. As the spirit, how does the player receiving your dream think? Will they see a picture of a cloud as the contents of the cylinder? Something rounded and metal as a cylinder, or just metal like the fork? Or are they one of those weirdos who sees a grey card and decides that the clue must also be grey, no matter how many times they’re proven wrong?

No matter what you choose, no matter how brilliant, there’s nothing as difficult as being the ghost and gritting your teeth when the investigators can’t figure out dream after dream.

Whodunit.

One of the great appeals of Mysterium is that it’s a rare cooperative game where alpha players can’t easily seize control of the proceedings. Sure, it encourages discussion, debate, and especially frustration when Real Geoff guesses that a red dream must mean the clue is red even when both the dream and suspect have distinct nautical themes. Even so, it’s not the sort of game where one player can simply dominate everyone else’s decisions. Better to get in sync with the spirit, listen to everyone’s thoughts, and then go with your gut.

The one downside seems to be that there simply aren’t that many dream cards. 84 doesn’t seem like a small number, but when you’re churning through over half the deck in a single sitting, it’s inevitable that a consistent group will begin to develop a sort of game-wrecking metagame: “Oh, Dan picked that nighttime pool to mean an inkwell last game, so Steve using it this time must also mean…”

It’s so similar to Dixit that it’s possible to import that game’s cards for more variety, though I’ve found that Mysterium’s cards tend to be denser and more open to interpretation. Our group whipped through the first few clues when we used our Dixit collection; then again, out of ten plays we have yet to solve the mystery in time, so maybe cheap tactics are exactly what we need.

I was already a fan of Dixit’s clever gameplay, and as a more directed experience Mysterium shines. It’s every bit as simple as its spiritual predecessor, and just as great for family or new players as it is for veterans. It has become one of our most-played games this year, moronic mute spirits notwithstanding.