BETHESDA, MD.: Lottie and Lisa look eerily similar, almost identical. But the two had never met before they wound up at the same summer camp. While forming a friendship, they share secrets that reveal why they look so much alike—turns out they’re actually twins who were separated when their parents divorced.

You may recognize that scenario from a familiar movie, The Parent Trap—which just happens to be the inspiration for Imagination Stage’s summer musical, Double Trouble, running through Aug. 14. The play includes details from not one but two movie versions of the story—the first starred a young Hayley Mills in 1961, with Lindsay Lohan taking over in the 1998 remake. But the story actually comes from German writer Erich Kästner’s 1949 book Lottie and Lisa.

Composer Marc Schubring, who will make his American debut with the show, landed the project for the company. “I had successfully adapted Emil and the Detectives as a musical in Berlin,” Schubring notes, so the rights-holder of Kästner’s book, Verlag für Kindertheater in Hamburg, Germany, “trusted me with this precious material.”

Schubring had collaborated earlier with playwright David S. Craig, who was already at work on an adaptation of the story, so the two joined forces. They modernized the story, eschewing the happily-ever-after movie ending.

“In the movie, the girls try to get their parents back together and they are successful, but we all agreed that this is old fashioned, and to depict that would be cruel to kids in divorced families,” Craig reasons.

Other modern touches include the girls using cell phones and more contemporary language. Personality-wise, one twin is an introvert, the other more outgoing.

“In the movie, they tried to find ways to make the girls different,” Craig points out. “We’re more interested in recognizing commonalities than in who falls into one category or the other.”