Copanatec by William Long

On his return to New Earth in the search for his parents, Archie is stranded when a timecrack lands him on the deck of Captain Abelhorn's fishing trawler, the Serpent. Along with Abelhorn's granddaughter, Kristin, Archie is captured by slave traders and taken to the island of Copanatec to work in the tunnels below the pyramid. Archie's brother, Richard, and Chuck Winters from the Facility in New Mexico, make the journey to New Earth. Despite the dangers they encounter, they are determined to find him.