***I WISH THIS BOOK HAD COME WITH INSTRUCTIONS***
So here: Start with whichever story you'd like. Gemma or Lyra. After each chapter, flip the book over and read the other characters chapter. Read and repeat.
I read Gemma entirely. Then Lyra entirely. I struggled with one story more than the other, but genuinely liked and enjoyed both. I believe I may have LOVED this book, had I read it properly.
The concept is awesome. The plot is great. When Helix comes out in 2017, I'll read it the right way and enjoy the stories the way they were meant to be.