At 2:45 on a Sunday afternoon, Jaclyn Pryor is wearing a suit and a yalmulke, running down an avenue in Hyde Park. Eight white Volvos trail behind her. A squadron of brides—including at least one man—look to the sky and take off running from an adjacent front lawn, joining the procession. Passers-by stand and gawk. Inside each Volvo, Pachelbel’s Canon plays. It is a perfect moment....

This Sunday afternoon, residents of Hyde Park might come across something a little strange—a group of cars driving slowly through the neighborhood, the passengers watching as actors perform a series of vignettes along the route they're traveling. This is the annual production of floodlines, conceived by Jaclyn Pryor seven years ago, and in its fifth of seven years of annual production (2010 will be the last year it's performed). Floodlines is this Sunday, 4/20......