Describe the relationship between Dennys and Sandy.

How did they respond to their time travel and why?

Compare and contrast the world the twins came from and the world they traveled to.

Compare and contrast the nephilim and the seraphim.

What was the significance of the stars and the wind for Yalith?

Why couldn't Yalith return with the boys?

Describe how the boys returned back to their time and how they had changed by the time they returned to the lab.