Okay here goes: I read a young adult book about orphaned psychic teenagers being studied in a laboratory when I was in middle school (90s). The main character was a teenage boy who somehow got separated from his guardian, a time traveler. The book itself was the last part in a trilogy, but the library never had books 1 and 2. The kids were being held against their will. Some of the experiments had the kids listening to ancient languages trying to figure out the meaning of the words. At one point, the main character gets mad and melts a red ball with just his thoughts. Spoiler alert: at the end the kids escape and are adopted by parents in some type of cold climate, Alaska maybe? The boy reunites with his guardian, and they go visit the ancient Egyptian pyramids. Funny, I can't remember the name or author, but I definitely remember the very end. Does this ring a bell to anyone? I'd love to read books 1 and 2. Thanks in advance!