THE IDEA OF REPRESENTING mental illness as a physical journey through a fantastical landscape is not a new one, but it gets an unusually elaborate treatment in Third Rail's current production of The Wonderful World of Dissocia. The show's first act takes place in the fantasy world of Lisa (Maureen Porter), a young woman abruptly plunged into a mysterious land—Dissocia is a twisted, loopy alternate reality, full of ridiculous characters (self-hating "insecurity" guards greet her at the border) and aggressive humor that occasionally tips into violence (she's nearly raped by a goat).

Dissocia features some of the most impressive technical design you're likely to see on a Portland stage this year—it's full of dazzling, "only in the theater" moments courtesy of designers Sam Kusnetz, Don Crossley, and Curt Enderle. The supporting cast sees Third Rail favorites like Philip Cuomo and Tim True deployed to great comic effect, and Porter helms it up admirably as a sort of overgrown Alice.

The show's second act, set entirely in the hospital room where Lisa is receiving treatment, abruptly immerses the audience in just the reality that Lisa is trying to escape: quiet, drab, devoid of color or music. Of course, it's also a half an hour of theater that is quiet, drab, and devoid not only of color and music but also of much in the way of dramatic conflict. I can't be the only audience member who wished for a return to the excitement of Dissocia—which is, I suppose, exactly the point.