Sister from the Multiverse (Choose Your Own Adventure) -- C. E. Berger, Paperback

4th Bestselling Children's Book Series of all Time -The New Yorker

You, along with your long-lost sister Veronica -- from a parallel universe -- must stop an evil scientist from obtaining technology that will help him take over the multiverse.

In C. E. Berger's CYOA debut, Sister from the Multiverse, you and your single mom live an ordinary life -- sure, she's always been a bit secretive about her job, but it's none of your business. That is, until a girl arrives outside your school one day claiming to be your long-lost sister... from a parallel universe! Does your mom's top-secret research at her science lab have something to do with it? And can you and your sister figure out how to unite your broken family and stop an evil scientist from using your mom's technology to take over the multiverse?

Choose Your Own Adventure is the bestselling gamebook series of all time. Empowering generations of children through choice, it is widely commended for its appeal to reluctant readers.