Andrew Long in “I Am My Own Wife.”

It’s the subtlety that gets you.

Andrew Long may be playing close to 30 different characters in Signature Theatre’s staging of I Am My Own Wife, but he transitions between them so naturally, so effortlessly, that it’s easy to relax into the pattern and forget that it’s just one guy up there. It’s an artful performance precisely on account of its lack of vanity. Long has a history of making a powerful, transfixing impression in roles ranging from the supporting to the familiar, so it’s almost surprising to see a softer, more delicate approach here.

Long’s “main event” character in I Am My Own Wife is transvestite Charlotte, whose unlikely survival through the Nazi occupation of Berlin is what transfixes playwright Doug Wright to focus his work on her (both in I Am My Own Wife and in reality). The meta approach to the work, fortunately, feels fresh rather than tiresome here. As the story unfolds, Wright’s pristine vision of Charlotte begins to crack. Reality battles with the symbolic status she holds in Wright’s mind, and, with the playwright also a character in the work, he’s not afraid to let us know how complicated it’s all becoming.