Jessica or Elizabeth?

Jessica Wakefield has fun pretending to be her twin sister, Elizabeth, one day when Elizabeth is home sick from school. Nobody can tell the difference!

Todd Wilkins thinks Jessica is Elizabeth, too. So he invites Jessica, thinking she's Elizabeth, to be in a television movie being filmed at his house. Can Jessica pretend to be her twin for a few more days and be in the movie, or will Elizabeth find out and get angry?