Way back in the early 2000s, a friend loaned me a book on cassette. I've been trying to track it down but I can't remember much about it. What I do remember:
- It was most certainly young-adult themed. The main character was a teenage girl, I think.
- The girl ended up living with her father (or perhaps grandfather), who she discovered was a scientist who was much older than he looked.
- I remember the word "Array" being used prominently.
- I recall a rival scientist who wanted the "array" for some nefarious purpose. He was also older than he appeared.
- I think that towards the end it was revealed that the "array" was used to prolong life and was not of terrestrial origin.
I think it was written in the late 90s. The word "Array" was on the cover, but I can't remember the rest of the title. I remember not finding it in my local library, and by the time Google became prominent, I had forgotten the title. What fragments of the plot I remember I've listed here.