The Forbidden Door - Dean Koontz

The Forbidden Door is the fourth novel in the Jane Hawk series.

Jane has to get to her son Travis. The fact that the Techno Arcadians are also trying to locate him just fuels her fire to find him. But the Techno Arcadians have miscalculated and their whispering room is turning into a huge problem. Jane has to find Travis, avoid the trap set for her, and keep from being caught in the whispering room horror that's been unleashed on a small Texas town. Very highly recommended.