Question: The whisper people bring the selected boy and girl to safety before the final day of earth. Why do they plant a message to be found and decoded just before the final day? I do not think the whisper people need any help from any humans to save humanity (and organize a whisperers' version of Noah's Ark).
Question: What do the rocks that the stranger in the car gives to Caleb mean?
Question: Why, near the end of the film, does Caleb start writing numbers which are supposed to be predictions of future events, when the world is going to end?
Question: Why did the grandmother get the codes if only kids will go to the new earth and not her?