The Code Solvers (Unabridged‪)‬

Eleven-year-old twins, Carolyn and Ben, happily lived with their parents until they were 3-years-old, when their mom died mysteriously. At 5, their father disappeared, too, leaving only a cryptic note behind. As the twins age, they discover that there may be more to the note than meets the eye. Follow the twins in their journey to discover their dad.