• Lutz Bacher's I Am Thinking How Happy I AmBaseballs II, at my feet, at Western Bridge. [The entire exhibition is called I Am Thinking How Happy I Am, based on something someone says in the soundtrack to Baseballs II.]

Hundreds of tipsy, emotional gallery-goers tried not to stumble and fall as they walked through Western Bridge's final opening party last Friday night. Baseballs were scattered on the floors of the gallery in Sodo, which opened in 2004 as the private project of collectors Bill and Ruth True, and which closes next month for good.

Western Bridge was always intended to be temporary, but it turned out to be so great—so important, so vibrant, the city's best exhibitions and best parties—that it was unsurprising to see tear-streaked faces.

The baseballs are an installation by Lutz Bacher, a lean, long-gray-haired cool customer of an artist (she was there, eating a brownie) who's lived and worked in Berkeley since the 1970s. The nervous-making yet melancholic artwork (those baseballs are dingy and just sitting there, their flying careers seemingly over) called I Am Thinking How Happy I AmBaseballs II was first seen at this year's Whitney Biennial in New York.

In addition to the balls scattered on the floors, the piece includes a blank video projected on one wall of the gallery. Playing on loudspeakers, though not loud enough to be heard over the din of Friday's party at Western Bridge, is a soundtrack that includes an exchange from The Unbearable Lightness of Being, in which lovers kiss after she asks him what he's thinking and he finally answers, "I am thinking how happy I am."

In the dark back room of the gallery, a small TV monitor sat on the floor playing a video also by Bacher. It showed a mittened hand finishing scribbling the words "AM HAPPY" on a handheld chalkboard to a few swelling strains of a string section. Then all at once, after just that handful of seconds it takes to finish scribbling the phrase, the video goes dark, the sound cuts out, and there's nothing. Until the video's totally ephemeral little self lights up the room and starts again. Each time it's a little birth and death.

"This place threw down a challenge to Seattle," one curator said. "Seattle, what are you going to do next?"