“It’s always been a dream to originate a role on Broadway,” says Virginia-born Grant Gustin, who had a nine-year run as the superhero the Flash on the CW series of the same name. In a musical version of Sara Gruen’s novel Water for Elephants, Gustin gets to do just that while he sings, dances, walks the trapeze, “and I even get to do some puppet work.” Gustin never felt as if he was stepping into the shoes of Robert Pattinson, who played the same role, of a veterinary student who falls in love with a ringmaster’s wife (played by Reese Witherspoon), in the 2011 movie. But, says Isabelle McCalla, who plays opposite Gustin each night at the Imperial Theatre, “I mean, if I’m going to step into anyone’s shoes, Reese Witherspoon’s are pretty tall and cute.”