Central Square Theater, Cambridge: *** out of 5. Three gifted women are having a ball playing all the roles in a British multigenre take on Arthur Conan Doyle’s most famous Sherlock Holmes story. Steven Canny & John Nicholson’s adaptation is along the lines of Patrick Barlow’s The 39 Steps, in which the script endeavors to hew to the original thriller tale but takes every opportunity to parody or exaggerate or even show contempt for it. A whiff of The Play That Goes Wrong is detectable whenever the cast purports to be so overwhelmed by the action and quick changes that they f— up pointedly. And there’s always room for a “meta” stepping-out, in which the players drop into their real names to bring out imagined jealousies or slights. Our suspension of disbelief in the silliness requires total commitment and pluperfect command, neither of which is quite there yet under Lee Mikesha Gardner’s direction, which could push harder for line accuracy and shave off a good 30 minutes or more. Still, it’s a jolly evening for the most part. Aimee Doherty bravely shoulders most of the burden of the plot, and I’d award Jennie S. Lee the Stan Laurel Laurel for drollness under fire. But for my money the merry sprite Sarah Morin is the MVP, lithe and sharp as a tack as Sir Henry Baskerville, the visitor from Toronto who sounds like Foghorn Leghorn: “We were expecting a Canadian accent.” “I can’t do that one.” Runs through Oct. 6; centralsquaretheater.org. (Photo of Lee, l. and Morin by Maggie Hall.)