All great books, though Hitcher was just good.

Writing serial science-fiction/fantasy is complex solving problem, good character interaction, tension, humor, plot twists - sometimes woven into one another, sub plots and universal questions such as:

Can anger be expressed effectively, without acting it out?

Can all conflicts small and gargantuan be solved through the ways of fierce peace instead of violence, murder and war?

Can we live without money, greed, divisiveness in a cooperative circular interactive group as opposed to a hierarchical world or group (patriarchy) or a horizontal world or group (matriarchy)?

Is Light Consciousness? Can light be used as fuel across the spectrum from the material to the spiritual?

Can universal love broadcast without an object, subject or single person reach everyone and melt fear?