Save here! This is the end, so you want to save in case you want to see a different ending.

You know you can't trust Saavedro, and you want the book back. So trap him to force him to give it to you. Run upstairs and turn off the power, which will activate both force fields. He won't be very happy. If you go near the fence. he'll pass the book through to you.

Now it's safe to let him go. Just make sure you have the switch flipped so that the OUTER field is the one that goes down before you turn the power back on!

And that's The End :)

The Myst 3: Exile Walkthrough