"Once Upon a Mattress" is playing at the Coterie Theatre June 19 to August 5. http://www.coterietheatre.org or 816-474-6552. Control-freak Queen Aggravain chases off her son's chances of finding a princess by creating unbeatable tests. Along comes klutzy Princess Winnifred (who swims the moat from the swamp) to set the Prince's heart aflame. So, the Queen plans her most difficult challenge yet. The palace is filled with merriment and mischief while everyone wonders if Princess "Fred" will pass the Queen's test. Based on Hans Christian Andersen's "The Princess and the Pea." Part of the Coterie's Family Series.