For hundreds of years the male members of the Kilcannon family have considered themselves beneficiaries of distortions in the statistical distribution of chance, associating their most fortunate windfalls with visual distortions they call "streaks." Canny Kilcannon is unsure as to how far he can go in tempting fate. Then he meets Lissa Lo, the female beneficiary of a similar centuries-old streak of luck. Lissa suggests that they attempt the ultimate biological experiment to test the boundaries of their gift. Can they succeed? Or will they bring down upon their heads the curse of "black lightning" about which both of their traditions warn. A truly compelling tale of luck and probability in the real world.