Bestselling horror novelist Dean Koontz and his longtime wife Gerda Ann are in the mood to mix up their Orange County, Calif. real estate portfolio. Just days before they paid $10.5 million for a home in Irvine’s scenic Shady Canyon gated community, the Wall Street Journal reported — and property records confirm — the couple very quietly sold their custom mansion in the uber-affluent Newport Coast neighborhood for exactly $50 million.