A successful installation at Suyama Space can be measured by a single metric: Does it feel like you haven't been in it before? The gallery itself is so distinctive—bellylike, with vaulted wood ceilings, creaky and splintery wood floors, and heavenward windows up top—that it overtakes any art that shows the slightest sign of weakness or sameness. Your memories of that art aren't of that art, they're of the space. On the flip side, a strong enough work of art will redefine the space and at the same time reveal aspects about it you hadn't noticed you'd been overlooking all along. Your memories of the space will be of this art. Dan Corson's new installation, Grotesque Arabesque, reveals Suyama Space to be the hull of a ship hurtling through deep sea or night sky, with a giant green hologram of a glowing grotto suspended in its pleasure-seekingly mirrored interior.

It feels as if this Suyama Space has been here all along waiting for a black light to illuminate it. (Could a site-specific installation get a higher compliment?) The hologram-like midair "drawing" of a cave is made of flat strips of steel. Each one is bent to form the curved shapes of the outlines of a cave's walls, including stalactites, and each strip is suspended from the ceiling at a precise height to create the illusion of a real, continuous hollow of a cave. Each strip is also lined on one side with electroluminescent tape made from the powder of actual mined phosphors; together with indigo gels applied to the skylights, the scene becomes a subterranean yet urban twilight, electronic and unearthly. Ramping up the sense of the fantastic is a giant reflecting pool filled with water on the floor and an 18-foot-long Mylar mirror on a far wall.

Let's face it: The natural and associative charms of a cave are always improved if there's water involved. Glistening, hard, dripping, lumpy walls are sympathetic and terrible both. And reflections underground, where there's no sky to imply infinity, manufacture their own endless but closed systems. Likewise, in Grotesque Arabesque, you never see it all; there's always a mystery more.

Caves are a major preoccupation in Seattle art this month, it would seem: Leo Saul Berk just opened an exhibition at Lawrimore Project (not seen before this story went to bed) based on cave forms connected to political realities and fictions (Tora Bora and Saddam Hussein's hiding place). Corson's cave is a Platonic ideal, an experiment in the essence of caveness, but it's not a modernist abstraction. It's linked in tone to the rest of his career, which is spent on the streets, making public art. This cave is a cousin to a series of stony waves Corson made in 2002 that sit under the Bell Street entrance to Highway 99, behind chain-link fencing. At night, they undulate with psychedelic colored light: natural forms not trying in the least to act natural. The public is as impenetrable as the private.

Not knowing has two sides: Not knowing is the greatest, not knowing is the worst. In the slight but refreshing group show False Proof at Kirkland Arts Center, not knowing—remaining in a state of possibility, running a continual loop of faith and disbelief—is mostly just great. Nola Avienne paints tiny alchemical symbols drawn from medieval sources using her own blood. She's committed to the mysteries. They stand for themselves, which is why you can't understand them. Eugene Parnell's life(?)-size, big-eyed Taxidermied Bigfoot gobbling the powdered doughnut of a hiker whose clothes and backpack lie at the creature's feet in the gallery is labeled as made of the following materials: "taxidermied bigfoot." Drew Christie's elaborate "historic" display of "evidence" about the Elliott Bay Sea Beast—a toothy Loch Ness Monster—collected and compiled by one Albrecht "Aesop" Ribbentrop is sometimes too cute but mostly irrepressibly endearing in its refusal to try to be convincing. You can hear the sound of the beast (it roars and gargles at the same time), see drawings and photographs of it, even look at instruments made in its honor by sailors just moments before they were eaten by it. Hanging in the middle of the room is the beast's skeleton: a happily false thing made out of barely disguised wood, glue, and newspaper. "I shall be vindicated," Ribbentrop's writings declare. Done.

A trophy twirling around on its head, defying gravity, would be more intriguing were it not happening in video—a medium in which disbelief is a given. That work is by Zack Bent. Jana Brevick's devices for problem solving are not served well here; you need to know that Brevick creates jewelry to fully understand these devices as talismans rather than too-sweet mini-sculptures. (My favorite, because it so clearly doubles as a necklace, is her Optimizer, a choker with a black box machine for a pendant. What's going on in there, who knows?)

In a video and diagram based on the Brady Bunch episode "Out of This World," in which Greg fools Peter and Bobby with a fake UFO (until the authorities are called and Greg is exposed), Chicago artist Jonathan Gitelson debunks the realness of the fake UFO by attempting to restage the hoax himself according to Bobby's on-show instructions. Fail. Gitelson's illustrated how-to diagram leaves intact the secret of how to. It hardly matters whether there is life on other planets when there is the magic of TV, which is not diminished in the slightest by not being magic at all.

Samantha Scherer's photorealistic velvety black watercolor and gouache paintings are on thick paper that curls up at the edges like it's entrapping its only subjects, little white faces peering out from the bottom of the paper's black universe as if they were almost entirely cropped out, à la "reality" video stills or photographs. (Blair Witch style.) Scherer's employing the clichés of horror-vérité but making them work again, much like in an older series where she appropriated the parade of corpses on Law & Order and made them feel individual again in her tiny drawings. Something in her handcrafted and yet utterly mediated approach demonstrates a recognizable struggle: Familiarity and unfamiliarity can be indistinguishable. Which is the worst.