  A simple procedure is given to construct curved, non-self-dual (complexified)
Kaehler metrics on space-time in terms of deformations of holomorphic quadric
surfaces in flat twistor space. Imposing Lorentzian reality conditions, the
Schwarzschild, Kerr, and Plebanski-Demianski space-times (among others) are
derived as examples of the construction.
