Tina Fey’s endlessly quotable 2004 movie is transformed into an endlessly quotable Broadway musical. (So fetch!) Led by the vicious Regina George, the Plastics are the popular girls who rule North Shore High School. Cady Heron, a new transfer student who grew up being homeschooled by her zoologist parents on an African savannah, is unexpectedly welcomed into the clique and then plots to destroy it from the inside. But things, of course, get complicated. Fey wrote the musical’s book, which updates her original story to the present day, complete with weaponized social media messages and timely new references. Casey Nicholaw (The Book of Mormon, Aladdin) directs.