Upside Down in the Jungle

Mad and Roo's world turns upside down when their bird-freak dad goes
to the jungle and doesn't come back. When they receive a Very
Strange and Incredibly Creepy Letter, which Roo swears is in code,
they know that something has happened to him.
Determined to find him, the girls set out into the Costa Rican jungle
to investigate. With the help of a golden-eyed boy, a rare and
valuable bird and some weird jungle flowers that grow between
Roo's toes, they fight to rescue their father.