The Pirate King by Laurie R King (2011) Bantam 

Another Mary Russell novel, this one a farce where Mary is sent on an undercover mission to investigate the theft of goods following a silent filming company on projects.  This project will be called The Pirate King and is about a company of actors doing the Pirates of Penzance as a film while getting kidnapped by real pirates, which the producers/directors have managed to hire as the pirate actors.  The characters are colorful and when they reach Morocco, they are imprisoned in houses and ransoms are set.  Mary manages to navigate the waters between the actors and the pirates, saving the crew and helping set the pirates on a more profitable course.  And land a starring role for herself in an interim film.