My only memory of Digital Fortress is that my mom sold our copy of it on eBay when I was midway through reading it and that still ever-so-slightly irks me almost two decades later.
You didn't miss much, but if you feel you need to find out what happened, get a library card and sign up with Libby, to borrow the ebook or audio book for free. The libraries near me don't even have a wait list for the audio book.