Adam Bock's funny new play is broken into five parts, or "flights," like a Russian ballet -- Narrative, Vision, Mad Scene, Conclusion, and A Little Dance -- but most of the action takes place during the Narrative section, which is pretty Mad, and tells the story of a family disintegrating after the mother dies. The husband (and father) believes her soul has entered a little wren, and builds an aviary to protect it. When the wren dies, he goes, too, and his daughter wants to replace the aviary with a Church of the Fifth Day. (God created birds on the fifth day of Creation.) The church idea causes a family crisis, and the crisis drives the play. Bock's dialogue is spare and suggestive, but it's never quite clear what he's suggesting; he seems more interested in his bird-soul motif than in any of his characters. The four flights after Narrative also feel tacked-on, unnecessary. Still, the formal problems don't prevent Alexis Lezin from giving a manic performance as the church-founding daughter, Olivia, or Kevin Karrick from portraying a hilarious professional hockey player who likes bake sales and ballet. A scene with four of the characters at a ballet (Swan Lake) is also brilliant. Bock's first play, Swimming in the Shallows, had a successful local debut in 1999, and Five Flights has all of that play's formal inventiveness but not quite as much of its charm.