This gift is apparently random, and can range from a minor telekinesis limited to lifting pencils to super-enhanced senses to teleportation to full conjuration of matter.
The main character, a philosophy major from Earth named Gene Ferraro, gains the power of superb swordplay.
His best friends include Snowclaw, a giant humanoid covered in white fur, who originally comes from a polar-like clime, and Linda Barclay, a woman from Earth who becomes a powerful sorceress.
However no one has a map, or knows where the Skyway begins or ends, and because each portal is one-way, only explored sections with a known return path (discovered by trial and error) are considered safe to travel.
At this point Jake is accompanied only by his father, Sam, who is actually dead but has been "converted" into an artificial intelligence unit that is built into the truck.